Ssh error while connecting using ssh key

How to Use GitLab
1

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 git@gitlab.com
The authenticity of host ‘gitlab.com (172.65.251.78)’ 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 ‘gitlab.com’ (ED25519) to the list of known hosts.
git@gitlab.com: Permission denied (publickey).

2

The authenticity of host ‘gitlab.com (172.65.251.78)’ 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 ‘gitlab.com’ (ED25519) to the list of known hosts.
git@gitlab.com: Permission denied (publickey).
fatal: Could not read from remote repository.

Does any anyone have any idea why this isn’t working?