WHMCS

Keep default configuration. By default the module is available for all customers who has active shared hosting product(s).

1. Go to "System Settings" → "Products/Services" (for WHMCS 7: "Setup" → "Products/Services" → "Products/Services") in WHMCS admin area.
2. Create new products for site builder. You can duplicate them from your current shared hosting products (but setup different name, price and other options for them). You can find more about WHMCS shared hosting products on this page: https://docs.whmcs.com/Products_and_Services.
   
   During product creation in WHMCS for Product Type choose "Shared Hosting" and in "Module Settings" tab for Module Name choose your hosting panel.
3. Go to "System Settings" → "Module Addons" (for WHMCS 7: "Setup" → "Module Addons") → button "Configure" next to "Site Builder".
4. Enter names of newly created shared hosting products into field Applicable Products.

After that those customers who purchase builder shared hosting products will be presented with a Site.pro builder button on their pages.

1. Go to "System Settings" → "Product Addons" (for WHMCS 7: "Setup" → "Products/Services" → "Product Addons") in WHMCS admin area.
2. Create addon for Site Builder (setup your name, price and other options). You can find more about WHMCS product addons on this page: https://docs.whmcs.com/Product_Addons.
   
   During product addon creation in WHMCS in "Module Settings" tab for Module Name choose "None".
3. Go to "System Settings" → "Module Addons" (for WHMCS 7: "Setup" → "Module Addons") → button "Configure" next to "Site Builder".
4. Enter the name of created product addon into field Product Addon Name.

After that all customers who have active shared hosting product will be presented with a purchasable Site.pro builder module with an extra price to their hosting. Once the client purchases the addon, the builder button will appear on his page.

1. Go to "System Settings" → "Product Addons" (for WHMCS 7: "Setup" → "Products/Services" → "Product Addons") in WHMCS admin area.
2. Create addon for premium builder with name "Site Builder Premium" (setup your price and other options). You can find more about WHMCS product addons on this page: https://docs.whmcs.com/Product_Addons.
   
   During product addon creation in WHMCS in "Module Settings" tab for Module Name choose "None".
3. Go to "System Settings" → "Module Addons" (for WHMCS 7: "Setup" → "Module Addons") → button "Configure" next to "Site Builder".
4. Make sure that the option Use as Product Addon is unchecked.
5. Go to licenses page https://site.pro/My-Licenses/, click "Manage" button in your brand (if you have no brands, then create one) and switch to section "Edit plans".
6. Find field "Default" and switch it for the desired builder plan which you want to be active by default (e.g. builder plan "Tiny" or "Free").
7. For builder plan "Full" in the field "Relate with these hosting plans" specify the following value:
   {"a": "Site Builder Premium"}
   You can find more details about how it works in documentation Editing plans.
8. Apply changes by clicking button "Apply" in the bottom of the brand.

After that all customers by default will have access to builder "Tiny" or "Free" plan (depending on which one you selected as default), and those who purchase the addon "Site Builder Premium" will have "Full" builder plan.
Value "Site Builder Premium" is used as an example. You can change it to your desired name.

1. Go to licenses page https://site.pro/My-Licenses/, click "Manage" button in your brand (if you have no brands, then create one) and switch to section "Edit plans".
2. Find field "Default" and switch it for the desired builder plan which you want to be active by default (e.g. builder plan "Full").
3. For builder plan which you want to be for subdomains (e.g. for "Tiny" or "Free") in the field "Relate with these hosting plans" specify the following value:
   {"d": [".example1.com", ".example2.com"]}
   You can find more details about how it works in documentation Editing plans.
4. Apply changes by clicking button "Apply" in the bottom of the brand.

After that all customers by default will have access to builder plan "Full", and those who have subdomains which end with either ".example1.com" or ".example2.com" will have "Tiny" or "Free" plan (depending on what plan you specified the condition for).
Values ".example1.com" and ".example2.com" are used as an example. Change them to your domains. You can also specify more of them or leave only one.