m.me is a shortened URL service operated by Facebook that redirects users to a person, page, or bot in Messenger.
You can use them on your website, email newsletters, and more. It works on mobile as well as desktop.
The format of the link is http://m.me/ PAGE_NAME , where PAGE_NAME is the handle of the Facebook page the bot is linked to.
This image shows where to find the name (or handle) of your Facebook page:
Facebook will occasionally add numbers to the end of your page handle, for example www.facebook.com/page-name-12345678. If this is the case, your bot link will only use these numbers. For example http://m.me/12345678.
Just like any other content you post online you can share this URL with people allowing them to directly access your bot. Give it a try: http://m.me/thebotplatform.