Ok nicklg. I just created a new KVM on my Proxmox server, installed CentOS 7 Minimal, installed CWP 7, installed WHMCS 7.4.1 (nulled only for testing, never for production server). Working on local IP address without any domain. On public IP with domain will be the same.
Here are screenshots:
Getting the module for WHMCS ->
Check WHMCS version (7.4.1) ->
See pending order ->
Accept pending order (you can select also "Send Welcome Email") ->
Order accepted ->
Check logs (Utilities -> Logs -> Modules Log) ->
Check in CWP7 if the user is created ->
Log in to CWP7 with the new user we just created ->
As you said that the CWP and WHMCS are on different boxes, add in /usr/local/cwp/.conf/api_allowed.conf the IP addresses of CWP and WHMCS. Waiting for your reply. BTW I put it FREE the hosting not to pay to PayPal taxes to transfer $1 from one of my cards to another in a testing. Working with price is the same.