Fritzbox Brume 2 Axt 1800 best configuration

hi! I’m on the internet via a Fritzbox Cable 6660. At the moment the Amazon fire cube is on the main port (port 1 with 2.5 gig) and port 2 is a switch for hue bridge PS4, TV, notebook etc. But I’m thinking about putting the switch on port 1 and plugging the PS4 TV fire cube directly into the other 1gih ports on the Fritzbox. I recently got a brume2 and AXT1800 (Slate AX). Unfortunately I don’t know how best to connect the two VPN routers to the Fritzbox? One option that I think is useful is if I turn off the WiFi on the Fritzbox I can access the internet via the WiFi on the slate. Can anyone give me some advice and instructions? Many thanks

Could you please elaborate on what’s your goal?

Hopefully, you don’t want to use your home internet for incoming VPN? Because this shouldn’t be possible since you are using a Cable Fritz!Box which indicated you might use Cable internet which is mostly behind CGNAT.