Nested Django Rest Framework Sterilizers

serializer.py

from rest_framework import serializers
from authentication.models import *
from authentication.serializers import RegisterSerializer


class UserSerializer(serializers.ModelSerializer):

    class Meta:
        #Notice there is no fields i the Meta class
        model = User
        exclude = ('password', 'groups','user_permissions')
        extra_kwargs = {
            'password': {'write_only': True},
            'another_field': {'read_only': True},
            'username': {'read_only': True},
            'email': {'read_only': True}
            #add other fields
        }

class ProvinceDetailedSerializer(serializers.ModelSerializer):
  
  #make sure you add required=False in the UserSerializer so that you don't get error of invalid created_by_id or whatever you user FK is
    created_by = UserSerializer(read_only=True,required=False)
    class Meta:
        model=Province
        fields = ('id','province_name','created_by','created_at')