When someone uploads an image, I want to add that image to my Gridster gallery - how do I do that?

So far, I've got my gridster gallery working just fine, but only if I specify the file location in css.

I would like users to be able to upload images, and they are automatically added to the gallery.

I have a foreach which provides me with the logo url for each image, but how do I get that into gridster for each image?

I guess I'd need to resize the images too, and maybe count them?

I'm using Laravel, Blade and Gridster.