RPi4b WLAN Connection help

Hi, I’m new on using freedombox, I have some Linux abilities, but the box setup it’s been a little hard.
My problem is, I do not have access to the router, but my RPi4b with an extra Wifi adapter (TP-Link AC600). And just after the first boot it shows a new wi-fi called FreedomBoxwlan0. The problem is I cannot access it so I can enter the web console. How can I login to the wifi? Or I really do need a router to setup?

My ultimate idea is to relay the internet from the University wifi via the freedombox wifi, and setup some server stuff on it.

Looks like the default wifi password is freedombox123 . Be sure to change this password (on System - Networks app) after you log in!