You wrote this code to enable TokenAuthentication but your API always returns 403 Forbidden. What is the likely mistake?

You wrote this code to enable TokenAuthentication but your API always returns 403 Forbidden. What is the likely mistake?

from rest_framework.authentication import TokenAuthentication

class MyView(APIView):
    authentication_classes = [TokenAuthentication]

    def get(self, request):
        return Response({"message": "Hello"})