Recently I had to setup a new Proxmox host and also had to setup a VPN to access the network of the host. This time I gave PiVPN a try, since it recently added support for Wireguard.
So first I installed Wireguard on the host like here (without adding the TUN device to the containers config), set up a new unprivileged container running debian buster, set up port forwarding in the router, installed curl followed by the one liner for PiVPN.
apt install curl curl -L https://install.pivpn.io | bash
And that was almost it. Now just add a device and use the QR-Code the use it on Android.
pivpn -a pivpn -qr
PiVPN delivers what it promises! That was super easy to setup.