how to add data to a many-to-many field in a Django REST API

Django REST framework (DRF) is a powerful and flexible toolkit for building Web APIs. It is built on top of Django, a popular web framework for Python. DRF provides a number of features that make it easy to build APIs, including:

• Serialization: DRF provides a number of sterilizers that can be used to convert Django models to and from JSON, XML, and other formats.
• Authentication: DRF provides a number of authentication mechanisms, including Basic AUTH, OAuth, and JWT.
• Authorization: DRF provides a number of authorization mechanisms, including Django's built-in permissions and custom permissions.
• Testing: DRF provides a number of tools for testing APIs, including a built-in API browser and a test client.
  

Many to many relationship in django model

1. Define the serializer for the model with the many-to-many field. The serializer should include a field for the many-to-many field. For example, if the model is called Movie and the many-to-many field is called genres, the serializer would look like this:
   

   class MovieSerializer(serializers.ModelSerializer):
       genres = serializers.ManyRelatedField(queryset=Genre.objects.all())

   
   
2. Define the viewset for the model. The viewset should include an action for adding data to the many-to-many field. For example, the following viewset would allow users to add genres to movies:
   

   class MovieViewSet(viewsets.ModelViewSet):
       queryset = Movie.objects.all()
   
       @action(detail=True, methods=['POST'])
       def add_genres(self, request, pk=None):
           movie = self.get_object()
           genres = request.data.get('genres')
           for genre in genres:
               movie.genres.add(genre)
           return Response(status=status.HTTP_200_OK)

   
   
3. Register the viewset with the API. To register the viewset with the API, add the following code to your urls.py file:
   

   from django.urls import path
   
   from .views import MovieViewSet
   
   urlpatterns = [
       path('movies/', MovieViewSet.as_view()),
   ]

   
   

You can also perform many-to-one, one-to-one and other relations with model reference like that, but always remember its require to add unique id of relationship model, otherwise getting error from api or which you have using like web forms.