You can take wallpaper from the Wallpaper Engine.
You can make your own wallpaper
You can find wallpapers on the internet
You can steal (I do not advise plagiarising)

We need to go into Wallpaper Alive
And select "Choose Wallpaper".
And we're in the software itself.
On the left, go to "Publish"
Fill in as you wish, choose tags.
Choose your wallpaper.
Attention, the size of the wallpaper should not exceed 2 MB.
Click on "Submit" and wait
Then go to the workshop and edit as desired

You can go to my Wallpaper Alive workshop and rate or put up my wallpaper