Django rest framework: пользовательский метод Generics для "RetrtieveUpdateDestroyAPIView(generics.RetrieveUpdateDestroyAPIView)" не работает

В этом общем APIView, когда я пытаюсь войти в систему через неадминского пользователя, он выдает "detail": "У вас нет разрешения на выполнение этого действия.", но все работает нормально для пользователя администратора.

Я не знаю, где проблема - в коде или в permission.py
. Я поделился своими Views.py, permissions.py и models.py для того же самого.

class BookingRetrtieveUpdateDestroyAPIView(generics.RetrieveUpdateDestroyAPIView):
    permission_classes = [IsUserOrIsAdmin]
    # queryset = Booking.objects.all()
    # serializer_class = BookingSerializer
    def get_queryset(self):

        if self.request.user.is_admin == False:

            user_data= self.request.user
            book = Booking.objects.filter(user= user_data)
            return book
        else:
            book = Booking.objects.all()
            return book

    serializer_class = BookingSerializer

permissions.py


from django.contrib.auth import get_user_model
from rest_framework.permissions import BasePermission

User = get_user_model()


class IsUserOrIsAdmin(BasePermission):
    """Allow access to the respective User object and to admin users."""

    def has_object_permission(self, request, view, obj):
        return (request.user and request.user.is_staff) or (
            isinstance(obj, User) and request.user == obj
        )

views.py

class User(AbstractBaseUser):
    email = models.EmailField(verbose_name='Email',max_length=255,unique=True)
    name = models.CharField(max_length=200)
    contact_number= models.IntegerField()
    gender = models.IntegerField(choices=GENDER_CHOICES)
    address= models.CharField(max_length=100)
    state=models.CharField(max_length=100)
    city=models.CharField(max_length=100)
    country=models.CharField(max_length=100)
    pincode= models.IntegerField()
    dob = models.DateField(null= True)


    # is_staff = models.BooleanField(default=False)
    is_active = models.BooleanField(default=True)
    is_admin = models.BooleanField(default=False)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    objects = UserManager()

    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['name','contact_number','gender','address','state','city','country','pincode','dob']

    def __str__(self):
        return self.email

    def has_perm(self, perm, obj=None):
        "Does the user have a specific permission?"
        # Simplest possible answer: Yes, always
        return self.is_admin

    def has_module_perms(self, app_label):
        "Does the user have permissions to view the app `app_label`?"
        # Simplest possible answer: Yes, always
        return True

    @property
    def is_staff(self):
        "Is the user a member of staff?"
        # Simplest possible answer: All admins are staff
        return self.is_admin


class Booking(models.Model):
    user =models.ForeignKey(User,on_delete=models.CASCADE)
    flights =models.ForeignKey(Flight,on_delete=models.CASCADE)
    passenger =models.ManyToManyField(Passenger)
    booking_number= models.CharField(max_length= 100,default=0, blank= True)
    booking_time = models.DateTimeField(auto_now_add=True)
    no_of_passengers= models.IntegerField(default=0,blank= True)

    def __str__(self):
        return self.booking_number

 def has_object_permission(self, request, view, obj):
        return (request.user and request.user.is_staff) or (
            isinstance(obj, User) and request.user == obj
        )