VPN access issue

The vpn is working but the users can’t access  the resources because the IP was change All the servers  only approved access from the Wan address of the Forti - it's white list

The IP of the server - users have to get access to it  is 20.101.142.72 Anyone who connected to the VPN would receive their address, and because of that, all they had to do was put the VPN's IP in the WHITELIST and that's it. That's exactly how it works at ROCKET too.

Can you help me to fix our problem?