Authenticate view for rest framework

views.py

class GetAccessToken(PermissionsMixin, View):
    authentication = [APIKeyAuthentication]
    form = UserForm

    def post(self, request, *args, **kwargs):
        user = authenticate(username=self.CONTENT['username'], password=self.CONTENT['password'])
        if not user:
            raise ErrorResponse(status.HTTP_400_BAD_REQUEST, {'detail': 'invalid username or password'})
        access, created = Access.objects.get_or_create(application=self.user, user=user)
        response_data = {
            'user_url': reverse('api-user', kwargs={'pk': user.pk}),
            'access_token': access.token,
        }
        return response_data