FRITZ!Box routers already support WireGuard VPN, you can try it now
AVM Fritz!Mesh Set International (Fritz!Box 7530 And Fritz!Repeater 1200, Dual-WLAN AC up to 866 Mbps (5 GHz) And N up to 400 Mbps (2.4 GHz), up to 300 Mbps through VDSL Supervectoring
How to configure VPN for Fritzbox 7530 AX - VPN Tracker