Need help understanding some values

[LorenzoBianchi02]

I am trying to use Gym-Eplus to train and compare different RL models.
I was able to run the example but I have some questions.
Firstly I don't know what possible actions can be passed to "env.step()".
Secondly I cannot find the meaning of the values of ob (returned by "env.step()").

Thanks in advance
@zhangzhizza