Better steps for your Wireguard installation.

[jumpsmm7]

The install procedure current method has often fallen to unreliable as the rpi-kernel and newer changes with kernel-headers with the RPI is ever evolving. here is what I recommend for new installation instructions for wireguard as they are more reliable then using unstable debians version.

echo "deb http://raspbian.raspberrypi.org/raspbian/ bullseye main" | $SUDO tee /etc/apt/sources.list.d/wireguard-bullseye.list
printf 'Package: *\nPin: release n=bullseye\nPin-Priority: -1\n\nPackage: wireguard wireguard-dkms wireguard-tools\nPin: release n=bullseye\nPin-Priority: 100\n' | $SUDO tee /etc/apt/preferences.d/wireguard-limit-bullseye

(this part below is already in your instructions)
sudo apt update && sudo apt install raspberrypi-kernel-headers wireguard wireguard-tools wireguard-dkms qrencode -y

I recommend keeping everything else the same.
I recommend switching to the raspbian/bullseye dev and telling it to only allow usage for wireguard and associated packages, this will insure the binaries always honor the kernel-headers.

[jumpsmm7]

I have submitted a pull request per my changes
#17

[jumpsmm7]

this will stage wireguard to be pulled from raspbian bullseye distribution and will set it up to limit it to ONLY for wireguard.