This feature is great for maximizing engagement and creating a viral effect on your Facebook Posts. When enabled, we are able to automatically message anyone who leaves a comment on your Facebook Page post. Once that person replies to your message they will automatically become a Facebook Messenger Subscriber.
Step 1: On the left navigation area click on "Lead Magnets"
Step 2: On the top right of this page click on the button for "New Lead Magnet"
Step 3: Select Opt-In Form and click Next
Step 4: Select Push Notifications in the Form type dropdown.
Step 5: Configure Your Opt-In accordingly.
For a full video walkthrough please watch this video below: