I found this image on insta (direct link for download that isn’t compressed by lemmy) and would like to use it as my phone wallpaper, so I need to extend the background to see the whole drawing. However I’m not very good with image editors, so I would only be able to add black borders, which is obviously ugly.

Can anyone extend the textured background so it’s about 3000x5000, so I can crop it to my liking? Thanks a lot in advance!