如何使用facebook唯一号码获取用户的电子邮件地址？

<a href="https://www.facebook.com/v10.0/dialog/oauth?
  client_id={app-id}
  &redirect_uri={redirect-uri}
  &state={state-param}
  &scope=email">Login with Facebook</a>

import requests

def get_access_token(app_id, app_secret, redirect_uri, code):
    url = 'https://graph.facebook.com/v10.0/oauth/access_token'
    params = {
        'client_id': app_id,
        'redirect_uri': redirect_uri,
        'client_secret': app_secret,
        'code': code
    }
    response = requests.get(url, params=params)
    return response.json().get('access_token')

def get_user_email(access_token):
    url = 'https://graph.facebook.com/me'
    params = {
        'fields': 'email',
        'access_token': access_token
    }
    response = requests.get(url, params=params)
    return response.json().get('email')

import requests
from flask import Flask, request, redirect

app = Flask(__name__)

APP_ID = 'your-app-id'
APP_SECRET = 'your-app-secret'
REDIRECT_URI = 'your-redirect-uri'

@app.route('/')
def home():
    return '''
        <a href="https://www.facebook.com/v10.0/dialog/oauth?client_id={}&redirect_uri={}&scope=email">Login with Facebook</a>
    '''.format(APP_ID, REDIRECT_URI)

@app.route('/callback')
def callback():
    code = request.args.get('code')
    access_token = get_access_token(APP_ID, APP_SECRET, REDIRECT_URI, code)
    email = get_user_email(access_token)
    return 'User email: {}'.format(email)

def get_access_token(app_id, app_secret, redirect_uri, code):
    url = 'https://graph.facebook.com/v10.0/oauth/access_token'
    params = {
        'client_id': app_id,
        'redirect_uri': redirect_uri,
        'client_secret': app_secret,
        'code': code
    }
    response = requests.get(url, params=params)
    return response.json().get('access_token')

def get_user_email(access_token):
    url = 'https://graph.facebook.com/me'
    params = {
        'fields': 'email',
        'access_token': access_token
    }
    response = requests.get(url, params=params)
    return response.json().get('email')

if __name__ == '__main__':
    app.run(debug=True)