If you want to connect to a host by using a password instead of a public key you can use the following command to initiate a request.
Note: This will only work if your host allows the user you are trying to connect with to authenticate by using password. Typically, this is disabled for root users and not advised to enable password authencation unless you really know what you are doing.
ssh -o PreferredAuthentications=password -o PubkeyAuthentication=no user@example.com