To save on iPhone or iPad:press + hold on the image, save. You can set separate lockscreen and home wallpapers under your phone settings. Or, second option—justclick the download button below (plus save & rename the image in your files app).
To save on computer:right click on image, save.
*weird tip:downloads are free for images that have a touchscreen-option to “save to photos” (a feature not 100% available, all of the time).