Hi Saviour,
The custom.css
file of the WHMCS template already linked up with the WHMCS template. In this issue, you don’t need to do anything.
Moreover, please extend your support period to get further assistance, because your FREE support period was expired on 2019-08-01.
Also, please post your topic in the exact/right/correct forum that item you have bought.
Best Regards,
ThemeLooks Support Team