By "it" do you mean Wireguard? I haven't used it, but you need a special type of virtual interface for bridging, a tap device can do it, a tun cannot. From so

By "it" do you mean Wireguard? I haven't used it, but you need a special type of virtual interface for bridging, a tap device can do it, a tun cannot. From some searches, Wireguard doesn't support operating on a bridge. OpenVPN, which is what I've used in the past, supports both tun and tap interfaces.