Reposting this link about stock art site.
Be careful about the licence. Not all stock can be used commercially (it will say). How are you with a bit of photo editing? You can quickly knock up something quite easily if you know how (but requires practice if you haven’t done it before. Not a bad thing to learn though). Example is this one that just has a little colour correction, small amount of manual shading, a filter and a title added. I didn’t want anything too time consuming to make as it was just for a speed game I wrote for itch, but it works as quick, free cover art. Even if you’re not up for photo editing, at the demo stage, even just the straight stock image will be enough to set the scene. I recommend against paying for commission art until you’re sure you want to publish it (and you can always make your own if you want to or costs are an issue.) As Eiwynn says, don’t use anything AI generated you want to use in publishing.
You mean like this?
It’s a png image. Choicescript is not easy to customise multiple texts on one page so adding images is usually easier. Make sure its png with a transparent background.