How do I create a list of documents on firebase console?

I already defined one of the fields of a document a list of users. But I can't seem to find how to do that on firebase console to make my app work.

Any ideas?

I am trying to do a language learning platform where the students view only the classes assigned by their teachers. I am trying to do that by adding a list of student's references in the class collection. If you have any smarter way to do that, I am open to learn.

Thanks a lot for this community! It has been very helpful for me to learn more how to use flutterflow!