api:https://api.weixin.qq.com/cgi-bin/message/mass/preview

请求参数：{"towxname":"wxid_cfdc0hefy7y711","mpnews":{"media_id":"AEqlCeLEXljfDqEwIuiWRXlhoVy4GBjKonM-Sx8XQr7weYXQvkY6WOPsyO1JIhOa"},"msgtype":"mpnews"}

返回信息：{"errcode":268488001,"errmsg":"system busy, please try later rid: 65b85be0-133ffaec-4542fd29"}

公众号id:gh_f66ae83f2277