title: How to do session management in react js app with flask as backend?
body: <p>Hello I am working on a web app created using create-react-app. I am using flask as backend. in flask I am using CORS and cross_origin. My app is as follows</p>
  
  <pre><code>import random
  from flask import Flask, request, session, jsonify, Response
  from dbconnect import POD_Admin_DB as dbAdmin 
  from flask_cors import CORS, cross_origin
  
  app = Flask(__name__)
  CORS(app)
  otp = "000000"
  app.secret_key = b'_5#y2L"F4Q8z\n\xec]/'
  
  @app.route('/api/requestOTP',methods=["POST", "OPTIONS"])
  @cross_origin(supports_credentials=True)
  def pod_requestOTP():
      print('requestOTP')    
      session['otp']=generate_code()
      print((session))
      print (session['otp'])
      #userPhone=request.json['userPhone']
      return session['otp']
  
  @app.route('/api/verifyOTP',methods=["POST","OPTIONS"])
  @cross_origin(supports_credentials=True)
  def pod_verifyOTP():
      if request.method =="OPTIONS":
          print("here")
          return Response(headers={"Content-Type": "application/json charset=utf-8",
          "Allow": "POST, OPTIONS",
          "Access-Control-Allow-Origin": "*",
          "Access-Control-Allow-Headers": "Content-Type",
          "Access-Control-Allow-Methods": "DELETE, GET, HEAD, OPTIONS, PATCH, POST, PUT"
          })
      elif request.method == "POST":
  
          print("verifyOTP")
          print((session))
          #print(dir(request))
          print(request.data)
          otp = request.json['pod_Otp']
          print((otp))
  
          userPhone=request.json['userPhone']   
          print(userPhone)    
          if otp == session['otp']:
              print("otp matched")
              dbAdmin.connectToDb()
              dbAdmin.isClientAlreadyRegistered(userPhone)
              return jsonify({"ok":"success"})
          else:
              print("otp not matching")
              return jsonify({"Notok":"success"})
  
  #some method that generates my otp
  #def otp_generationMethod():
      ###code
  </code></pre>
  
  <p>this is my flask code.
  I access these both routes from my react app. Everytime when I fetch the pod_verifyOTP() method after requestOTP() from my session from flask becomes empty.
  I searched many references for this problem but could not fix this.
  How should I maintain this session? </p>