pip install "gymnasium[atari]"
Then install auto-rom via:
pip install "gymnasium[accept-rom-license]"
or:
pip install autorom
AutoROM --accept-license
or, if you can not download the ROMs, you can download them manually from Google Drive. Then, you can install the ROMs via:
pip install autorom
AutoROM --source-file <path-to-Roms.tar.gz>
python train_ppo.py