nixCraft published a guide about setting up WireGuard VPN server on Ubuntu Linux 20.04 LTS.
Ubuntu 20.04 set up WireGuard VPN server
A step by step guide helps you configure and set up WireGuard VPN on Ubuntu 20.04 LTS server and a Linux desktop client, including ufw configurations.
Ubuntu 20.04 set up WireGuard VPN server - nixCraft