This part of the site is a small repository of free images of this unfeasibly beautiful planet and some of its stupid residents, pre-collapse, added as they're processed. Most are configured as desktop wallpapers (16:9 ratio). If there are any you would like to use or adapt for your website or any other project, please go ahead.
Is there a need to credit this site or whoever held the camera? No
Are there any limitations? Just one. The original image shouldn't be on-sold or NFT-tokenized. But if you make use of parts of an image as the basis for (or elements of) a separate creative project, e.g. the background for a brochure or slide-pack, that's fine. Rename at will.
Do I need to contact anyone? No. Please don't.
Setting an image as desktop wallpaper: there are various ways, e.g. on PC and using the image viewer IrfanView, select Options > Set As Wallpaper > Fill.