Groupboss is Facebook Group automation software comprising a Chrome extension, Dashboard and Website. By using Groupboss, you will be able to collect the answers of the questions that you have already set for your new members, provided that the new member has answered your questions. Also, you will be able to collect the Facebook ID link. To know more about the functionality of the Groupboss you can watch the Getting Started video here: Getting Started with Groupboss.
Here you'll find the documentation on how to set up the integaration: https://support.groupboss.io/intregration/mailerlite