I am trying to login to the aws instance using ssh and putty that having odoo v11 running, I followed different ways to get access but still, I cannot.

Errors in ssh : permission denied (public key) -> I was able to login with the same key suddenly I could not log in and no one changed the permission also I changed the key pairs but still, cannot log in

Errors in putty : It shows (server refused our key) -> I get the same message with the previous key and the new one

Also, I made an EBS-Backed AMI and launched a new instance using a new key and I am still not gaining access

So my question is how to check the .ssh configuration And how to backup PostgreSQL database and add it to newly created odoo.

Thank you