Ssh error while connecting using ssh key

hi all,

I’m new to gitlab, and using github for years without any troubles about ssh keys

while following Use SSH keys to communicate with GitLab | GitLab, i got
this error:
my pub key is added on gitlab web site

ssh -T
The authenticity of host ‘ (’ can’t be established.
ED25519 key fingerprint is SHA256:eUXGGm1YGsMAS7vkcx6JOJdOGHPem5gQp4taiCfCLB8.
This key is not known by any other names
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added ‘’ (ED25519) to the list of known hosts. Permission denied (publickey).