Some Avatar websites don't make it easy to save what you created.
Try Using your computer to save it.
On a Mac: use <command> <shift> <4> to do a partial screen grab. When the tiny box appears, stretch the corners to cover just the portion of the screen you need. It will save to your desktop where you can save it or import it to other sites.
On a home PC: Download the free Snipping Tool and use it to save your avatar.