ModelSerializer foreign key relation issue in multi database DRF project

Question

In my DRF project, I use multiple databases to handle the data I don't specify a default database in settings.

whenever I use the model serializer with ForeignKey relation Django emits the following error

settings.DATABASES is improperly configured. Please supply the ENGINE value. Check settings documentation for more details.

I know why this error is prone because by default ModelSerilizer sets the field of an FK relation like this

serializers.PrimaryKeyRelatedField(
        queryset=ItemCategory.objects.all(),
        required=True, allow_null=False)

because I don't have a default DB it will show that error it's fine

to overcome I did something like this

class ItemSerializer(serializers.ModelSerializer):
class Meta:
    model = Item
    fields = ('id', 'name', 'category')

def __init__(self, instance=None, data=..., **kwargs):
    user = kwargs.get('context').get('user')

    database = user.db
    self.fields['category'] = serializers.PrimaryKeyRelatedField(
        allow_null=True, queryset=ItemCategory.objects.using(database).all(), required=False)
    super().__init__(instance, data, **kwargs)

but when I print the field category it returns something like this

PrimaryKeyRelatedField(allow_null=True, queryset=<QuerySet [<ItemCategory: ItemCategory object (1)>]>, required=False)

instead of the query param, it assigns the querySet

is there any solution for this (I am not sure assigning the fields manually from init method works fine)