FinRL_HyperparameterTuning_Optuna.ipynb has error

the file [FinRL_HyperparameterTuning_Optuna.ipynb](https://github.com/AI4Finance-Foundation/FinRL-Tutorials/blob/master/4-Optimization/FinRL_HyperparameterTuning_Optuna.ipynb) gives me the following error

```
TypeError Traceback (most recent call last)
Cell In[17], line 16
3 env_kwargs = {
4 "hmax": 100,
5 "initial_amount": 1000000,
(...)
13
14 }
15 #Instantiate the training gym compatible environment
---> 16 e_train_gym = StockTradingEnv(df = train, **env_kwargs)

TypeError: __init__() missing 1 required positional argument: 'num_stock_shares'
```

when defining env_kwargs, how can I fix this?

just adding some random number for num_stock_shares throws the error `TypeError: can only concatenate list (not "int") to list`