To the knowledge base

Using WireGuard VPN with a fixed IP address

The FRITZ!Box only supports WireGuard when used with a MyFRITZ! or dynamic DNS address. This ensures that WireGuard connections can can be established from mobile networks that have already been converted from IPv4 to IPv6 as well as from Wi-Fi hotspots or company networks that do not support IPv6 yet.

You can also use MyFRITZ! or DynDNS if you are using the FRITZ!Box on an internet connection with a fixed ("static") public IPv4 address. The FRITZ!Box can then be reached via its MyFRITZ! or DynDNS address under both the fixed IPv4 and the changing IPv6 address. If both MyFRITZ! and DynDNS are configured in the FRITZ!Box, the FRITZ!Box uses the MyFRITZ! address for the WireGuard connection.