session is not being saved google Authentication, state saved to session is lost, in callback

I am trying to access the latest email from gmail. and I have done allt he due delegence like dowonloading the credintials form google console, but the problem arises when I am trying to save the state into session, that session when accessesd in oauth2callback , the session is lost. I have tried everything no progress.

view.py

from django.shortcuts import redirect, render
from django.conf import settings
from google_auth_oauthlib.flow import Flow
import os
from django.http import HttpResponse

# Mock settings for this test. Replace with your actual credentials and URIs
REDIRECT_URI = "http://localhost:8000/authenticate/oauth2callback/"
SCOPES = ["https://www.googleapis.com/auth/userinfo.email"]


def gmail_authenticate(request):
    flow = Flow.from_client_secrets_file(
        os.path.join(os.path.dirname(__file__), "credentials.json"),
        scopes=SCOPES,
        redirect_uri=REDIRECT_URI,
    )
    authorization_url, state = flow.authorization_url(prompt="consent")

    request.session["state"] = state
    return redirect(authorization_url)


def oauth2callback(request):
    state = request.session.pop("state", None)
    if not state or state != request.GET.get("state"):
        return HttpResponse("Error: State does not match.", status=400)

    # Assuming success for simplicity
    return HttpResponse("Success")

settings.py

"""
Django settings for oauth_test project.

Generated by 'django-admin startproject' using Django 4.2.3.

For more information on this file, see
https://docs.djangoproject.com/en/4.2/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/4.2/ref/settings/
"""

from pathlib import Path

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/4.2/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!


# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = [
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    "django.contrib.sessions",
    "authentication",
]

MIDDLEWARE = [
    "django.middleware.security.SecurityMiddleware",
    "django.contrib.sessions.middleware.SessionMiddleware",
    "django.middleware.common.CommonMiddleware",
    "django.middleware.csrf.CsrfViewMiddleware",
    "django.contrib.auth.middleware.AuthenticationMiddleware",
    "django.contrib.messages.middleware.MessageMiddleware",
    "django.middleware.clickjacking.XFrameOptionsMiddleware",
]

ROOT_URLCONF = "oauth_test.urls"

TEMPLATES = [
    {
        "BACKEND": "django.template.backends.django.DjangoTemplates",
        "DIRS": [],
        "APP_DIRS": True,
        "OPTIONS": {
            "context_processors": [
                "django.template.context_processors.debug",
                "django.template.context_processors.request",
                "django.contrib.auth.context_processors.auth",
                "django.contrib.messages.context_processors.messages",
            ],
        },
    },
]

WSGI_APPLICATION = "oauth_test.wsgi.application"


# Database
# https://docs.djangoproject.com/en/4.2/ref/settings/#databases

DATABASES = {
    "default": {
        "ENGINE": "django.db.backends.sqlite3",
        "NAME": BASE_DIR / "db.sqlite3",
    }
}


# Password validation
# https://docs.djangoproject.com/en/4.2/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        "NAME": "django.contrib.auth.password_validation.UserAttributeSimilarityValidator",
    },
    {
        "NAME": "django.contrib.auth.password_validation.MinimumLengthValidator",
    },
    {
        "NAME": "django.contrib.auth.password_validation.CommonPasswordValidator",
    },
    {
        "NAME": "django.contrib.auth.password_validation.NumericPasswordValidator",
    },
]


# Internationalization
# https://docs.djangoproject.com/en/4.2/topics/i18n/

LANGUAGE_CODE = "en-us"

TIME_ZONE = "UTC"

USE_I18N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/4.2/howto/static-files/

STATIC_URL = "static/"

# Default primary key field type
# https://docs.djangoproject.com/en/4.2/ref/settings/#default-auto-field

DEFAULT_AUTO_FIELD = "django.db.models.BigAutoField"

SESSION_ENGINE = "django.contrib.sessions.backends.db"