Centos – How to add new user accounts with SSH access to the Amazon EC2 Linux instance

I'm trying to access new user which is created in AWS instance using SSH, but it throws an error when i execute the command ssh -i new_keypair.pem new_user@54.XXX.XXX.XXX

Error : Permission denied (publickey,gssapi-keyex,gssapi-with-mic)..

I followed each and every steps as mentioned in AWS document https://aws.amazon.com/premiumsupport/knowledge-center/new-user-accounts-linux-instance/

Please Let me know is there any additional configurations are required to access newly added user using SSH..