This one is quite simple. You will need to modify the ssh config file which is located at /etc/ssh/sshd_config.
Open the /etc/ssh/sshd_config file with your favorite editor.
Find or add the line PasswordAuthentication
Enter the value ‘yes’ next to PasswordAuthentication
It should look like:
Save and exit the file. The restart the ssh deamon with the below command:
service ssh restart – Ubuntu and family
service sshd restart – CentOS and family