Unfortunately, I can't give you a backup configuration, but I can give you screenshots of the working WireGuard configuration.
Here the main aspects are that we need IP address that is 10.0.0.1 on server side (RUT240).
And peer configuration:
Public Key of client-side (Android). Allowed IP must be the one from the client (Android): 10.0.0.2 and endpoint host WAN IP of Client (Android).
Address of the client: 10.0.0.2
Public key of the peer must be server-side (RUT240) public key. Allowed IP: 0.0.0.0/0 and endpoint of server-side (RUT240) WAN IP.
Hope this helps.