When I try to add my registration form to Facebook I get this message: You must have permission to add apps to at least one Facebook page to perform

To be able to add your form to a Facebook page,  you need at least one active tab.  The following guide has information on how to add a tab to a Facebook page and then add a form to that tab:

https://www.jotform.com/help/22-Adding-a-Form-to-Your-Facebook-Page