hiii @Haarwurm ,
welcome to the Dietpi family, 
Can be seen here: No Wi-Fi hardware found? - Troubleshooting - DietPi Community Forum
or else :
[RPi 3 Model B] fresh install of bullseye: Wifi (adapter) not found - Troubleshooting - DietPi Community Forum
Wi-Fi RPi 4 - No supported WI-FI hardware was found · Issue #4770 · MichaIng/DietPi · GitHub.
Sincerely