How to encrypt an image (and other stuff) graphically on linux

Hi, I want a nice easy-to-use graphical program which can show image thumbnails atleast, and provide an easy way to encrypt images, and ideally other files too. I heard of a few programs but some dont show images and some look a bit dated ui wise. Seeing image thumbnails is pretty much a requirement as it would be alot of swapping back and forth otherwise.

I am using KDE (and nixos), I dont think that matters much for what I want.