If you’re trying to create a #chatbot for blog and you get the “this person isn’t available right now” error while testing, all you need do, is to enable messaging on your Facebook page.
How?
Sign in to your Facebook account and go to your page
Click on “Settings” > “Messages”
Click on edit and enable people to contact your page privately as seen in the screenshot below.
Ensure you save the settings.
That’s all.