The Facebook Join My Mailing List application is designed to only be added to business or organization pages. I am sorry for any inconvenience this has caused you. I recommend that you add this to a Facebook page and ask people in your groups to visit this page to sign up. This would be a great way to direct traffic to your organization's Facebook page!
Please let us know if there is anything else we can do for you.
-Curtis P Community & Social Media Support
If you find my post helpful, and it answers your question, please mark it as an "Accepted Solution" by clicking the Accept as Solution button in the bottom right hand corner of this post.
Increase your profitability by integrating your email marketing and social media. Download this guide and learn how you can achieve great results with email marketing and social media combined!