Token authentication in Django Rest Framework

INSTALLED_APPS = [
    .
    .

    '<your_app_name>',
    'rest_framework',
    'corsheaders',

    'rest_framework.authtoken' #new
]

REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': [
        'rest_framework.authentication.TokenAuthentication',
    ],
}

from rest_framework.views import APIView
from rest_framework.decorators import api_view
from rest_framework.authtoken.models import Token
from django.contrib.auth.models import User
from django.core.exceptions import ObjectDoesNotExist
from rest_framework.response import Response
from django.contrib.auth.hashers import check_password

@api_view(['GET'])
def getData(request):
    users = User.objects.all()
    users_serializer = MyUserSerializer(users, many=True)
    return Response(users_serializer.data)

class TokenAuthentication(APIView):    
    def post(self, request, format=None):
        data = request.data
        if('username' in data):
            try:
                user = User.objects.get(username=data['username'])
                checkPassword = check_password(data['password'], user.password)
                if(checkPassword):
                    #If token is not created, the following will create a new token for the user instance.
                    token,created = Token.objects.get_or_create(user=user)
                    token_data = {
                        "user_id": user.id,
                        "token": token.key
                    }

                    return Response(token_data)
                else:
                    return Response("Password is incorrect.")
            except ObjectDoesNotExist:
                return Response("Invalid user details")
        else:
            return Response("Please fill the form.")

from django.urls import path
from . import views

urlpatterns  = [
    path('', views.getData),    
    path('token_auth/', views.TokenAuthentication.as_view())

]

from rest_framework import serializers
from django.contrib.auth.models import User

class MyUserSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = "__all__"