Completed successfully, Thanks a lot @abbas for your support.
Some learned lessons I would share here:
1-don’t modify sshd_config unless you are done and sure, else you risk to be out of the home and keyless, also before starting modification do a backup of that file.
2-I have used ed25519 and not rsa, this one give an error at the end and you cannot login.
3-ssh key works for a specific computer and specific windows unix user. in my case I am using windows laptop, I have installed different bash (ubuntu for windows, mobaxterm) I can use only ubuntu for windows to connect to VPS server using ssh, if use mobaxterm connection refused.
rgds
Nofal