Setting up Port Forwarding for AT&T (ISP) BGW320-500 Router/Modem

Technical Support for Routers VPN, DNS, Leaks
6
  1. Confirm if the ISP router has the public IP - confirming
  2. Regarding the Port Forwarding for WireGuard Server:
    Global Port Range: 51820
    Base Host Port (GL router WireGuard Server): 51820
    Protocol: UDP

I set the above and the port forwarding is working successfully.