Cant access port menu

I downloaded the Arduino ide on my raspberry pi 4 and am trying to upload a sketch to my Arduino uno. When I try to upload a sketch I get the error message serial port not selected, so I got to the tools tab and the ports menu is greyed out.

Welcome to the forum

Which version of the IDE have you installed ?

Does the Pi recognise the Uno is plugged in ?

Do you by any chance also have the stm32 boards package installed? On my Windows PC I need to downgrade that to version 2.7.1 because 2.8.0 onwards it is not compatible with the old IDE anymore and screws up my COM ports.