Upscaling is very useful if you aren’t able to generate large enough images with an AI. If you want to upscale AI art, you should use AI upscalers. Check out this image for a comparison of different programs. Once you pick which one you want, just search it in any search engine, and you should be able to find instructions in the official github repo. Although the comparison image is embedded in this page, it’s highly recommended to open it in a new tab so that it isn’t automatically scaled down.