Wireguard

Follow these guides:

• https://www.freecodecamp.org/news/build-your-own-wireguard-vpn-in-five-minutes/
• https://www.wireguardconfig.com/

But note that `AllowedIPs` on the client should be `AllowedIPs = 0.0.0.0/0, ::/0` to use as a VPN for everything (more detail here: https://docs.pi-hole.net/guides/vpn/wireguard/route-everything/)