This may be helpful if you haven’t found it yet. It has a full list of instructions to flash and configure openwrt on the rpi 4 with wireguard VPN. It says you can also do it with openvpn, but claim the speed was much slower.
https://www.instructables.com/Highspeed-VPN-Router-With-Raspberry-Pi/
This may be helpful if you haven’t found it yet. It has a full list of instructions to flash and configure openwrt on the rpi 4 with wireguard VPN. It says you can also do it with openvpn, but claim the speed was much slower.
https://www.instructables.com/Highspeed-VPN-Router-With-Raspberry-Pi/