Hi any chance of bringing this to FlowXo.
Message to FB post comment.
Available in ManyChat
Alternatively a way to run this thru ManyChat and then have a takeover by FlowXO would also work.
Unfortunately our bots don't yet have the functionality to detect comments left on a page. You could look into using Facebook's Instant Replies to do what you require. If you need to link to one of your bots you could also use the m.me link (see Creating a Facebook Messenger Bot) in your auto-response.