No link to localhost pages

I would like to use this plugin to create sliders on an offline webpage shown on a screen. When clicking on an image I want to link to a page. But when I put the image url starting with https://localhost/ I get the message: “Please enter a valid URL.” Is it possible to link to offline pages? I don’t bother to buy the pro version, but I’d like to know if this would work first.

https://www.ads-software.com/plugins/wp-responsive-thumbnail-slider/