Not able to send Asynchronous message on Wechat

Question

I was trying to develop an chatbot on wechat. I am usign wechat offical sanbox development to test the flow of the bot. I already have 3 follower to my offical wechat account. I am using one of the follower's openID in the post body. when I try to send an post request on https://api.weixin.qq.com/cgi-bin/message/custom/send?access_token=access_token

with post data as

`{
    "touser":"oQ-DXWEFAAk59QVI6hTgs96",
    "msgtype":"text",
    "text":
    {
         "content":"Hello world"
    }
}`

my postman hit the url and within few ms , I got response as

{
  "errcode":45015,
  "errmsg":"response out of time limit or subscription is canceled rid: 65afc2f9-77279a5c-426230e5"
}

cuse of this error and solution to start with Asynchronous processing