If you do have admin status on a Facebook page you will not be able to connect to Node. 

To confirm that you're the admin on a page on Facebook go to the associate page and select Settings. Next, select Page Roles.

Your role must be displayed as an Admin or Page Owner here. 

If you're using Facebook Business Manager for your Facebook Page you will need to visit your Business Manager page and confirm that you are an Admin for the page you are using to login to Node