微信服务号授权域名

// 引导用户进入授权页面
const authUrl = `https://open.weixin.qq.com/connect/oauth2/authorize?appid=YOUR_APP_ID&redirect_uri=YOUR_REDIRECT_URI&response_type=code&scope=snsapi_userinfo&state=STATE#wechat_redirect`;
window.location.href = authUrl;

// 用户同意授权后，微信会回调到YOUR_REDIRECT_URI，并带上code参数
app.get('/callback', (req, res) => {
  const { code } = req.query;
  // 使用code换取access_token
  fetch(`https://api.weixin.qq.com/sns/oauth2/access_token?appid=YOUR_APP_ID&secret=YOUR_APP_SECRET&code=${code}&grant_type=authorization_code`)
    .then(response => response.json())
    .then(data => {
      const { access_token, openid } = data;
      // 使用access_token和openid获取用户信息
      fetch(`https://api.weixin.qq.com/sns/userinfo?access_token=${access_token}&openid=${openid}`)
        .then(response => response.json())
        .then(userInfo => {
          console.log(userInfo);
        });
    });
});