Add forms tab to my facebook page

Hi there

I am trying to do this per the instructions but it says I don't have permission to do so.  Can you please let me know why that is so.

Hi there - Perhaps your Facebook page has less than 2000 likes. Kindly note that it's not possible to add a custom tab if you have less than 2000 fans.

Reference: https://developers.facebook.com/docs/pages/tabs 

If you need further assistance, please let us know.