The meaning of "actions.actions" in CMD ["start", "--actions", "actions.actions"] for rasa-sdk dockerfile

In the last line of rasa-sdk Dockerfile, there is “actions.actions”. What does it mean?

I’m somehow confused about the location of actions.py, should I put it in an “actions” folder or outside of it? And also, where should I put the __init__.py and some custom python package file, like aaa.py, which is being used as from aaa import bbb in actions.py. I tried to put aaa.py in actions folder with actions.py together, it can’t be found.