How can I add a full width mosaic/masonry image gallery? Elementor free

Hey everyone

I am looking to add a full width masonry image gallery to a website. I can’t seem to find any way to do it without a paid plugin. This website is for a friend so no money is being made.
I would like him to be able to select multiple images at once and add them to the gallery.
Does anyone know how I can do them or if any free plugins allow this? It seems so simple but I can’t find anything.

I’m using elementor free with the hello elementor theme.

Thanks