Accessing resources across apis

I have the following resource and api structure

resource : PyqRatta.Databank.Question
resource: PyqRatta.Databank.Quiz has_many PyqRatta.Databank.Question
api : PyqRatta.Databank → [PyqRatta.Databank.Quiz, PyqRatta.Databank.Question] (list of resources in api)

and

resource : PyqRatta.QuizPractice.Response belongs_to PyqRatta.Databank.Question
api : PyqRatta.QuizPractice → [PyqRatta.QuizPractice.Response] (list of resources in api)

now, in response.ex

    relationships do
        belongs_to :question, PyqRatta.Databank.Question,
          attribute_writable?: true,
          attribute_type: :integer,
          allow_nil?: false
    end

I am getting error. App Name is PyqRatta

* (EXIT from #PID<0.93.0>) an exception was raised:
    ** (RuntimeError) Resource `PyqRatta.Databank.Question` in relationship `:question` is not in api `PyqRatta.QuizPractice`. Please do one of the following

1. add the resource to the api `PyqRatta.QuizPractice`
2. configure a different api

I can see the relationship can be used for resource in different api.
Here, Red.Accounts.User is in api Red.Accounts and Red.Practice.Card is in api Red.Practice.
https://github.com/dewetblomerus/red/blob/ee1aab452d35cfe1687791d8e9423b32f26e915a/lib/red/practice/resources/card.ex#L111-L117

Why does it work in case above and not in my case?