https://developers.weixin.qq.com/doc/offiaccount/Message_Management/Template_Message_Interface.html

发送模板消息的文档有错误，参数

 "miniprogram":{
             "appid":"xiaochengxuappid12345",
             "pagepath":"index?foo=bar"
 }
应该是
 "miniprogram":{
             "appid":"xiaochengxuappid12345",
             "page":"index?foo=bar"
 },