WHMCS License Addon Insallation

Im after someone to finish of a WHMCS License Addon installation the issue is in the file you need to add the code for the license key i can't seem to get it to work Im adding it to a copy of oscmax Need experienced programmer to do this Budget $30 as half of the work has been done for you only need to link the file and the license key to WHMCS No Access to support system is required i can test it for you and advise if its working correctly