I am trying to do SSH in my instance. But it is showsing me the below error.
C:\Users\NADIM AKTHAR>ssh -l ec2-user 126.96.36.199 -i key123.pem
The authenticity of host '188.8.131.52 (184.108.40.206)' can't be established.
ECDSA key fingerprint is SHA256:FnoSXFNxXBt73s6wR3sXr57b4591FotlHugLqWFMDaw.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '220.127.116.11' (ECDSA) to the list of known hosts.
Load key "key123.pem": invalid format
firstname.lastname@example.org: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).
How can I solve this?