how to add button in slack in rasa code example

Example: how to add button in slack in rasa

@slack_webhook.route("/webhook", methods=["GET", "POST"])
        async def webhook(request: Request) -> HTTPResponse:
            if request.form:
                output = request.form
                payload = json.loads(output["payload"][0])
                if self._is_interactive_message(payload):
                    sender_id = payload["user"]["id"]
                    text = self._get_interactive_response(payload["actions"][0])
                    if text is not None:
                        # metadata = self.get_metadata(request)
                        out_channel = payload["channel"]["id"]
                        users = payload["user"]["id"]
                        metadata = {'out_channel': out_channel, 'users': users}
                        return await self.process_message(
                            request, on_new_message, text, sender_id, metadata
                        )
                    elif payload["actions"][0]["type"] == "button":
                        # link buttons don't have "value", don't send their clicks to bot
                        return response.text("User clicked link button")
                return response.text(
                    "The input message could not be processed.", status=500
                )