SK is right about uploading your image to the Free PostImage site. You check how long you want it to last up there.

Remember Lori's old Windows Computer Help Group?

https://mb.boardhost.com/WindowsOSHelp/

I uploaded the image for that group to that Post Your Image place and said for it to last there forever. And so far it has.

The code to post it there looks like this.

<img style="max-width:100%;" src="https://i.postimg.cc/VL1ThvFS/Header-For-Windows-OSHelp.jpg">