In order to customize the messages your users get when they unsubscribe, you need to go to your settings page from the left menu and follow the steps below :

  1. From Facebook Messenger go to Main Menu.
  2. Select the Main Menu item with the title Subscribers.
  3. Click Customize:

You will get an option to edit the default text under When someone unfollows, the bot will say:

For more on customizing your menu items, click here.

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