How to change logon screen on macOS?

[AjTee]

Hello,

I would like to change my logon background.

I tried solution from this site:

https://www.howtogeek.com/howto/29503/how-to-change-the-logon-background-in-os-x/

But, for me replacing file does nothing. It show blurred wallpapers from my desks.

Can you give advise how to use custom background?

Rgds, Jacob