There is a very well done step by step guide by Aaron in another tread:
With his help to change something in his nice tool, I managed to have everything working using WireGuard on a Raspberry Pi. Lean, quick, stable, no problem at all so far.
Not sure if it fits your needs, but it worked great for me. By the way, I had setup WireGuard in any case, Aaron helped me to have Roon core in my local network visible from devices connected via VPN from outside.
There is another tread explaining in details how to setup WireGuard on a gateway, if it might help: