How to do many to many in active model serializer?

Question

I'm looking for a solution to use many to many association in active model serializer.

Let's say I have a user with many user types through a many to many table, how can I return the user types for a specific user?

Do I need to create a serializer for the many to many model?

Answer 1

The answer was pretty stupid. I had set the serializer to "has_one user_type", a simple change to "has_many user_types" worked.