https://developers.weixin.qq.com/miniprogram/dev/framework/open-ability/subscribe-message.html

返回的结构体

{
	"CreateTime": 1688953684,//文档中为字符串，实际返回unix的int64
	"Event": "subscribe_msg_popup_event",
	"FromUserName": "o8dH44seYM3qeBzHlrmwI0sAtSfI",
	"List": {
		"PopupScene": "0",
		"SubscribeStatusString": "accept",
		"TemplateId": "BDcgTGpwt7fcRVFhGh-NvjcASaWWmkwzN3y_6mXzJR4"
	},//文档中为[]struct，但实际订阅单消息为struct
	"MsgType": "event",
	"ToUserName": "gh_xxxxxxxxxx"
}