https://www.whmcs.com/developer-friendly/
With our developer tools you have all the flexibility you need to customise WHMCS to make it your own. From simply changing the look and feel to integrating...
developer toolscustomisationwhmcs
https://whmcs.community/forum/41-developer-corner/
Integration, customization and module development, if you have questions, ask them here.
developer cornerwhmcs community
https://whmcs.community/topic/306814-add-funds-restricted-by-user/
I need to restrict the Add Funds page to a select list of users. I found the following hook written by Brian!, and modified it: I would like to display some...
developer cornerwhmcs communityaddfundsrestricted
https://whmcs.community/topic/350350-custom-pdf-invoices-header-and-footer-tpl/
Anyone can confirm that "invoicepdffooter.tpl" if working? I created a file in WHMCS 8.13, as mentioned in Customer PDF Invoice, with test text but...
developer cornercustompdfinvoicesheader