How to understand Permissions in django?

Question

Django

I can't figure out how to implement a user/group system in Django. That is, I understand users how to create, edit, etc. - I implement my model through AbstractBaseUser. But here's how to give them special permissions and put them in a group. For example, I need 3 groups - Users, Premium, Admin. And everyone should have the rights of the previous groups (ex. Premium has the rights of a premium and a user, the admin, respectively, has both a user and a premium and an admin).
I know and have already implemented my Permissions and Group by simply creating such tables in the database, respectively, and assigning the necessary ones to the user (for example, the user has the permissions attribute through ManyToManyField and I put the permissions I need there, also with groups). It seems to be much easier, but I'm afraid that when I get to some project with the team, they won't quite understand me)) And I think, why implement what is already in janga.
I use Python3, Django2.2