ppo code running error

[cxw-droid]

Hello, can you take a look at the following error? Thanks.

run code experiment.py

annotated_deep_learning_paper_implementations/labml_nn/rl/game.py

Line 130 in a0679ec

 obs = cv2.cvtColor(obs, cv2.COLOR_RGB2GRAY) 

cv2.error: OpenCV(4.9.0) 👎 error: (-5:Bad argument) in function 'cvtColor'
Overload resolution failed:

• src is not a numerical tuple
• Expected Ptrcv::UMat for argument 'src'