Cannot Activate on Dev Site

My client has an existing site on Drupal at https://www.womenworking.com

They have been running FB Instant Articles for years now.

We are switching them over to a WP site and I installed this plugin and got an ID but when I click o the blue LOGIN WITH FACEBOOK button it doesn’t do anything, no popup (popup blocker is off). it just refreshes the page without an error message.

This is frustrating and the client needs this installed ASAP!

Is it possibly not wrking because their FB page is already associated with an account and we are trying to connect on this dev site?