How to reenable Nouveau after uninstalling NVIDIA proprietary drivers?

**Problem:** My Nvidia graphics card requires 340.x drivers, so I tried installing an older-than-most-recent driver to see if it could help me. It did not help, and now I that I removed it, I cannot get any other resolution on my screen, besides 1024 x 768. **Steps taken:** 1. apt install nvidia-legacy-390xx-driver (old, but not enough); 2. apt remove nvidia-drivers (too newer than 340); 3. apt-get install --reinstall xserver-xorg-core libgl1-mesa-glx because [someone on the internet said it would work](https://askubuntu.com/questions/360761/cannot-get-rid-of-nvidia-drivers-restore-nouveau-driver-and-get-desktop-working) . 4. apt install nvidia-drivers 5. apt remove nvidia-smi 6. apt-get install --reinstall xserver-xorg-core libgl1-mesa-glx again, because [someone on the internet still says it would work](https://askubuntu.com/questions/360761/cannot-get-rid-of-nvidia-drivers-restore-nouveau-driver-and-get-desktop-working) . This did not restore the resolution to the normal that I used before. On the settings through GUI, I can only set 1024 x 768. How to fix Nouveau on Debian 11?