[paxys]

How do you use the router's VPN when you are not at home?

[mfiro]

After setting up the Wireguard on the router (Fritzbox), you get a QR code or config file which you can import to any Wireguard client.

[paxys]

What happens when your ISP rotates the IP address assigned to you?

[mfiro]

Fritzbox assigns a domain for the router, something like DynDNS. The config is bound to this domain.