"These instructions were written using a fresh install of the 2020-05-27 build of Raspberry Pi OS based on Debian Buster. If you use a different build you may need to fiddle a bit with kernel headers and other packages to get Wireguard installed. Eventually Wireguard will likely come baked into Raspberry Pi OS. You can use this link to download the 2020-05-27 Raspberry Pi OS software package. "