Form designer for Facebook Messenger apps?

I'm a veteran programmer, however I am new to the Facebook Messenger API. I have seen that the API does support buttons as per this code snippet from the Facebook developers web site that uses a CURL example to demonstrate the formatting code:

https://developers.facebook.com/docs/messenger-platform/send-api-reference/button-template

curl -X POST -H "Content-Type: application/json" -d '{
  "recipient":{
    "id":"USER_ID"
  },
  "message":{
    "attachment":{
      "type":"template",
      "payload":{
        "template_type":"button",
        "text":"What do you want to do next?",
        "buttons":[
          {
            "type":"web_url",
            "url":"https://petersapparel.parseapp.com",
            "title":"Show Website"
          },
          {
            "type":"postback",
            "title":"Start Chatting",
            "payload":"USER_DEFINED_PAYLOAD"
          }
        ]
      }
    }
  }
}' "https://graph.facebook.com/v2.6/me/messages?access_token=PAGE_ACCESS_TOKEN"

This looks like typical JSON to me. Is there a GUI tool that can design these layout elements, not only for buttons, but for any other Facebook Messenger form template elements that may also exist in the API? Something that uses a drag and drop or other GUI interface that then generates the necessary JSON code or fragment to represent the designed form?

If so, please leave its name or a link to it.

Solution

There is the Platform Design Kit for Sketch: https://developers.facebook.com/docs/messenger-platform/design-resources/design-kit