I use WireGuard on my router (ER-L) and Pi-Hole on the router as well, with a primary DNS on my Synology which uses Pi-Hole's Docker image [1]. Docker runs on Raspberry Pi, so I recommend you look into that route. Jessfraz wrote a howto on running WireGuard in Docker [2]

[1] https://github.com/pi-hole/docker-pi-hole

[2] https://blog.jessfraz.com/post/installing-and-using-wireguar...