How to use telethon in Flask

Here is my code in flask and i get an error after calling auth_code asking me to call send_request first. `

import json
from flask import Flask
from flask import Response
from telethon import TelegramClient
from telethon.tl.functions.contacts import GetContactsRequest
from telethon.tl.types import UserStatusOffline

api_id = 1000000
api_hash = 'XXXXXXXXXXXXXXXXXXXXXXXXXXX'

app = Flask(__name__)


@app.route('/auth/<phone>', methods=['POST'])
def auth_phone(phone):
    client = TelegramClient("my_name", api_id, api_hash)
    client.connect()

    response = {'code_sent': False}

    if not client.is_user_authorized():
        client.send_code_request("+{}".format(phone))
        response['code_sent'] = True

    return Response(json.dumps(response), 200, mimetype="application/json")


@app.route('/auth/<phone>/<code>', methods=['POST'])
def auth_code(phone, code):
    client = TelegramClient("my_name", api_id, api_hash)
    client.connect()

    if not client.is_user_authorized():
        client.send_code_request("+{}".format(phone))
        client.sign_in(phone, code)

    response = {'logged_in': False}

    if client.is_user_authorized():
        response['logged_in'] = True

    return Response(json.dumps(response), 200, mimetype="application/json")`

Please make sure to call send_code_request first.

Thanks in anticipation.