I did follow this guide from Techno Tim, he uses cloudflare but you can go with Lets encrypt aswellhttps://www.youtube.com/watch?v=liV3c9m_OX8
I followed this to access my homelab via VPN and the connect to protonvpn. Giving me local access and public IP fro. Proton!https://www.linuxserver.io/blog/advanced-wireguard-hub
I did follow this guide from Techno Tim, he uses cloudflare but you can go with Lets encrypt aswell
https://www.youtube.com/watch?v=liV3c9m_OX8