I am following a tutorial on Reinforcement Learning, I want to save my model using Gymnasium, but I get this error. Googling I didn’t find anything useful. I am running the code on Jupyter I also tried to run the simple script with Python but nothing changed

import gymnasium as gym 
from stable_baselines3 import PPO
from stable_baselines3.common.vec_env import DummyVecEnv
from stable_baselines3.common.evaluation import evaluate_policy
import os


environment_name = "CartPole-v0"
env = gym.make(environment_name, render_mode="human")
observation, info = env.reset(seed=123, options={})

model = PPO('MlpPolicy', env, verbose=1)
model.save("TrainingSaved ModelsPPOSaved")