Shortcode on page doesn't seem to work

Looks great as a post but with a page reading [custom-photo-gallery] it just shows a little outline square. (I’d like to attach a screen shot or two but don’t see any way to)

I have the site in maintenance mode as it’s not ready for users to register yet. If there is a trick to this do let me know. Otherwise when the site is live I’ll post on this forum again.

How to use on page
When photo gallery options setup done
then copy shortcode from top of Gallery Settings [custom-photo-gallery]

then paste this shortcode anywhere in your page to display Photo Gallery

https://www.ads-software.com/plugins/responsive-photo-gallery-wp/