Note: Before you can add a call to action button for your Facebook Page’s Bot, you must first have successfully setup and added your Page’s Page ID, Page Access Token, chosen a page name, and linked your Verify Token and Callback URL.
Head to the Facebook Page that you would like to create a call to action button for. Under your page’s cover photo area, you will see Add a button. Click this, then select Use Our Messenger Bot. Make sure that you have your Bot Builder set up correctly to respond appropriately. For instance, make sure that your Bot Builder has “when receive” “Click” set to GIGA_GET_STARTED_PAYLOAD and the appropriate “Bot will” response(s) that you would like the bot to respond with.