获取用户的UnionId

https://api.weixin.qq.com/wxa/getpaidunionid?access_token=ACCESS_TOKEN&openid=OPENID
请求这个接口获取用户的UnionId报下面这个错误

“{“errcode”:40101,“errmsg”:“missing parameter hint: [rhOdwnNre-1WOgFA] rid: 5f227843-50aa9cf2-51467ce2”}”