how to check sha256 key on server ? code example

Example 1: read fingerprint ssh-keygen

$ ssh-keygen -lf ~/.ssh/id_rsa.pub
2048 00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff /Users/username/.ssh/id_rsa.pub (RSA)

$ ssh-keygen -E md5 -lf ~/.ssh/id_rsa.pub