"Get Started" button does not appear in welcome screen for FB Messenger bot

Question

I followed the solution in this thread and it is still not working how to setup "Get started" button in facebook messenger bot and when to send welcome message

I tried both graph.facebook.com/v2.6/me/thread_settings?access_token=xxxxx and graph.facebook.com/v2.6/page_id/thread_settings?access_token=xxxxx with the raw body

{
  "setting_type":"call_to_actions",
  "thread_state":"new_thread",
  "call_to_actions":[
    {
  "payload":"USER_DEFINED_PAYLOAD"

   }
 ]
}   

The response message is like this

  {
  "result": "Successfully added new_thread's CTAs"
 }

But the message in welcoming screen just keep displaying "Type a message..."

Please help. This is so frustrating. The document on FB developer site is not helpful at all https://developers.facebook.com/docs/messenger-platform/thread-settings/get-started-button

Answer 1

I found the solution. The "Get Started" button does not appear because I used the users who are not "Tester" for my app ( but the Welcome text appeared that why I confused)

Answer 2

There are a number of bugs/issue that seem to affect if the button appears or not once it is finally set using the POST request, this is what I have found.

You need to delete the conversion on facebook.com chat not messenger.com or mobile App. Click the little gear thing in the chat window to do this.

Once deleted on fb.com the button will appear the next time you try to chat on fb.com and on messenger.com

The button will not appear on any previously used Android Messenger clients after deleting on fb.com

To make the button appear again on Android Messenger client you need to clear the Messenger data/cache under Android Settings -> Apps , this will also clear your login and you need to login again.

I don't have an iOS device.