文档地址： https://developers.weixin.qq.com/doc/offiaccount/User_Management/Get_users_basic_information_UnionID.html

订阅号，调用 https://api.weixin.qq.com/cgi-bin/user/info ，返回的响应体类似于：

{
    "subscribe": 1,
    "openid": "XXX",
    "nickname": "XXX",
    "sex": 1,
    "language": "zh_CN",
    "city": "XXX",
    "province": "XXX",
    "country": "中国",
    "headimgurl": "XXX",
    "subscribe_time": 1594368470,
    "remark": "",
    "groupid": 0,
    "tagid_list": [],
    "subscribe_scene": "ADD_SCENE_PROFILE_CARD",
    "qr_scene": 0,
    "qr_scene_str": ""
}

因为接口是调用成功的，所以accessToken和openId肯定是没问题的，但是其中就是没有unionId字段返回，求教！