I am trying to do ssh in my AWS instance. But I am getting this error.
C:\Users\Akhtar\Downloads>ssh -l ec2-user 18.104.22.168 -i myfirstkey.ppk
The authenticity of host '22.214.171.124 (126.96.36.199)' can't be established.
ECDSA key fingerprint is SHA256:HtO4bkrMd+bieuGVGZ9SKAFxQn4lGQU270cs0hUQjpU.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '188.8.131.52' (ECDSA) to the list of known hosts.
Load key "myfirstkey.ppk": invalid format
firstname.lastname@example.org: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
Can anyone tell me why I am getting this error?