You can use this command:
ssh -o PreferredAuthentications=password username@host
ssh to use
password as the authentication method.
The methods available for authentication are: GSSAPI-based
authentication, host-based authentication, public key authentication,
challenge-response authentication, and password authentication.
Authentication methods are tried in the order specified above, though
protocol 2 has a configuration option to change the default order:
More about ssh authentications, please check