Looks like it was for https://store.gx.me/mods/funzaf/worlds-2025/. Not sure if you have that mod installed and Opera was trying to update it or if you previously tried to install it, but it failed and Opera keeps retrying or if you have Early Bird turned on and the Daily Wallpapers feature turned on and Opera was fetching the wallpaper from that mod.
Doesn't seem to be anything malicious though.