In general it is strongly recommended to use a compatible wifi router. In that way several devices can be connected at the same time and the connection is less prone to interference.
Most accounts (not all) with move-in date on the renting contract AFTER January 2022 do use the new IPoE system.
Which system is in use for your StudNet account can be found in the registration e-mail (Startup).
For most StudNet accounts with move-in date on the renting contract BEFORE February 2022 you need to set up an Internet login on the connected device to be able to use the Internet. This means installing the VPN connection, which is necessary for connecting to the Internet.
To connect other unsupported devices like:
you will need a wifi router.