Consequently, clients may buy products in bundles along with flexible promo codes.
Module will also allow you to view, filter and delete existing connections used by your customers.

We will guide you step by step through the whole installation and configuration process.

In the most recent versions of the module, you will find only one package that supports PHP 7.2 and later.

The first one that supports PHP 5.6 up to PHP 7.1, and the second one addressed to PHP 7.2 up to PHP 7.4.
Note: Keep in mind that PHP versions 5.6 up to 7.1 are no longer officially supported and their security issues are not fixed or released any more. Find more info here.

The content of the package to upload should look like this.

File is located in 'modules/addons/productlinker/license_RENAME.php'. Rename it from 'license_RENAME.php' to 'license.php'.

Enter your license key between quotation marks as presented on the following screen. You can find your license key in our client area → 'My Products'.

Log in to your WHMCS admin area. Go to 'Setup' → 'Addon Modules'. Afterward, find 'Product Linker' and press the 'Activate' button.

To do so, click on the 'Configure' button, select administrator groups which should have access to this addon and press 'Save Changes'.

There, press 'Enable Debug Logging'.

You can access your module at 'Addons' → 'Product Linker'.

It also automatically forwards basic commands from the main product to all child products.
You can define relation between products through product addon or configurable option. You will find more information about it in the 'Add Relation' section.

They will be triggered once your client makes an order for product, with the product addon/configurable option chosen at the relation, and runs the Create command for that product.
Additionally, you can define a promo code added to the order by triggering the relation.

Note: For 'Addon' type there is also the 'Swap Price' option available. If you select it, the price of the linked hosting/product will be overwritten with the addon price.

If you have chosen the 'Configurable option' relation type, additionally you have to select a configurable option value.

Choose a promo code that will be added to the order and save the relation through pressing the 'Add Relation' button.
Note: Only one promo code can be assigned to the order, you can specify the assignment of promo code at the 'Settings' page.

You can alter one relation or multiple relations simultaneously, the only difference is the button used to save changes.
If you are making changes in only one relation, press the 'Save Changes' button next to it, otherwise use 'Save Changes' at the bottom of the page (pointed with a green arrow).

To create a new configuration simply choose product which will trigger the relation from the 'Product' dropdown menu. Next, select a product which will be added from the 'Linked Product'
dropdown menu. Optionally, assign a promo code and enable configurable option copying (if possible). Press 'Add Relation' to save relation.

To enable copying, mark checkbox next to configurable options and press 'Save Changes' as shown on the screen below.
Note: You can enable configurable option copying only if configurable option is assigned to both products.

You can find all information about a relation, like main product, linked product, their owner or domain used by both products.
You can quickly move to the customer or any of their products by simply clicking on a client/product name.

For example, to order by client name, press on the 'Client Name' column header as shown on the following screen.

To open filters form, press 'Toggle Filters'.

When you select values you desire, click the 'Filter Results' button (red arrow).
If you decide to clear filters you have set up earlier, open filters form and press 'Clear Filter' (green arrow).

Error messages can be found at the 'Clean Response' and 'Parsed Response' columns.
To locate products for which an error occurred, you can use data at the 'Request Parameters' column.
For example, '[accountid]' and '[domain]' should be enough to quickly localize products.
Note: Module also checks if the module log is turned on and provides a link to it.

All you have to do is enter value of '[accountid]' in place of account_id in the link below.

your_whmcs/admin/clientsservices.php?id=account_id

To confirm if you are looking at the right product, check if a domain in the product matches the domain you found in the error log.

Due to the assignment of promo codes to the relation, it may happen that multiple promo codes will be assigned to one order form. WHMCS does not support such actions,
therefore only one promo code has to be chosen.
1. 'Highest Discount Available' - if checked, the promo code giving the highest discount to your clients will be chosen at the order form.
2. 'Discount Limit' - if 'Highest Discount Available' is disabled, the promo code giving the closest discount to the value provided will be chosen.
Discount has to be greater than the value provided.

One of the many possibilities is connecting cPanel Manage2 For WHMCS, DirectAdmin Licenses For WHMCS and Odin Key Administrator For WHMCS with other products.
This will allow you to automatically provision ready to use licenses for clients once they order a product of your choice, e.g. a VPS server.
Note: Before following any of exemplary configurations below, make sure that both products you will be using in the configuration are set up correctly.
Additionally, product linked to the main product should be set to hidden and free. You will be able to set its price at the product addon.

Note: You can also link them using configurable options.
1. Start from creating the 'IP' custom field at the main product visible on order form.
To do so, go to 'Setup' → 'Products/Services' → 'Products/Services' and edit your cPanel Extended product.

Confirm changes through pressing 'Save Changes'.

Go to 'Setup' → 'Products/Services' → 'Products Addons' and press 'Add New Addon'.

It is advised to set up the same billing cycle as in the main product. Additionally, you have to mark 'Show on Order' checkbox and checkbox next to the main product.
In this example it will be 'cPanel - cPanel Extended'.
Next, press 'Save Changes'.

Do not forget to type the domain and IP address. Afterward, press 'Submit Order'.

Note: You can also link them using configurable options.
1. Start by creating the 'IP' custom field at the main product visible on the order form.
To do so, go to 'Setup' → 'Products/Services' → 'Products/Services' and edit your DirectAdmin Extended product.

Confirm changes through pressing 'Save Changes'.

Go to 'Setup' → 'Products/Services' → 'Products Addons' and press 'Add New Addon'.

It is advised to set up the same billing cycle as in the main product. You also have to mark the 'Show on Order' checkbox and the checkbox next to the main product.
In this example it will be 'DirectAdmin - DirectAdmin Extended'.
Next, press 'Save Changes'.

Do not forget to type in the domain and IP address. Afterward, press 'Submit Order'.

It is required to set a key type in your 'Odin Key Administrator' → 'Module Settings' to 'VIRTUOZZO'.
Only in this way a linked product will create a license for a Virtuozzo VPS product.
Note 1: You can also link these products using configurable options.
Note 2: In order to create a license successfully, you have to select at least one feature from the dropdown menu.

To do so, go to 'Setup' → 'Products/Services' → 'Products/Services' and edit your VirtuozzoVPS product.

Additionally, you can enter a description of this custom field and set up field validation (it is a one line validation, do not split it into two lines):

/\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)

\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b/

Confirm changes through pressing 'Save Changes'.

Go to 'Setup' → 'Products/Services' → 'Products Addons' and press 'Add New Addon'.

Choose billing cycle from the 'Billing Cycle' dropdown menu. It is advised to set up the same billing cycle as in the main product.
Additionally, you have to mark the 'Show on Order' checkbox and checkbox next to the main product. In this example it will be 'Odin Group - VirtuozzoVPS'.
Next, press 'Save Changes'.

Do not forget to type the IP address. Afterward, press 'Submit Order'.

There are a few key types in your Odin Key Administrator that are licenses for Plesk Extended.
In this example we will use 'PLESK_10_AND_LATER' key type.
Note 1: You can also link these products using configurable options.
Note 2: In order to create a license successfully, you have to select at least one feature from the dropdown menu.

Go to 'Setup' → 'Products/Services' → 'Products/Services' and edit your Plesk Extended product.

Additionally, you can enter a description of this custom field and set up field validation (it is a one line validation, do not split it into two lines):

/\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)

\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b/

Confirm changes through pressing 'Save Changes'.

Go to 'Setup' → 'Products/Services' → 'Products Addons' and press 'Add New Addon'.

Choose billing cycle from the 'Billing Cycle' dropdown menu. It is advised to set up the same billing cycle as in the main product.
You also have to mark the 'Show on Order' checkbox and the checkbox next to the main product. In this example it will be 'Odin Group - Plesk Extended'.
Next, press 'Save Changes'.

Do not forget to type an IP address. Afterward, press 'Submit Order'.

Let's take a look at an exemplary situation.

and allowed to purchase two addons along with it:
- cPanel License
- Direct Admin License
Our Test Tester client decided to add a cPanel License to the cart next to the VPS product.
Thanks to the connection created in the Product Linker addon, the final price is lower than as if the two items were ordered separately.

You need to remove the link between the old linked product and the main product in the addon, and terminate the old linked product manually.

Keep in mind there is a quick and easy option in our client area that will let you upgrade the license of your module to an open source version at any time - and at a lower price!
To take advantage of it, simply use the License Upgrade button located on the product's page and a discounted invoice will be generated automatically.