The auto responder is a keyword-based growth and support tool (FAQ). When a user messages a set keyword, it will trigger an after action. As a keyword "start" is a very popular choice, users are already familiar to that.
To set things up, go to "Grow > Add Growth Tool > Auto Responder".
With the auto responder set up, all people need to do is texting the keyword (e.g. "start") you defined. The keyword can be communicated through use of all kind of channels - whether it's LinkedIn, YouTube, Radio, ...
Promote keyword in Facebook Page's title image
Turn Facebook Page visitors into subscribers. Get their attention by adding a quick instruction on your Cover Image. This is how it could look like: