Password protecting your server
If you'd like to require a password for access to your server this can be configured in the server properties.
Edit the server properties
Enter the password that will be required to connect into the Password box. This is a password you will give out to other users so make sure not to use one of your own passwords.
Press OK. You will be asked to confirm the password that you entered. Re-enter the same password.
Press OK. Users will now be required to enter this password before they can connect to your server.