As mentioned on latest changelog, We allowed non-premium players to join. And we add an Authentication system on a server which need you to /login before entering our server. Here's some information about this system.
For Non-premium user
You can now enter the server! But you need to /login everytime you enter the server just to make sure that the person logging in to our server is really you.
WARNING! If you choose to skip the authentication (which basically use Mojang authentication instead), You won't be able to log in to the server again! If you click on it by accident and can't revert it, please contact admin on discord.
For Premium user
Next time you login to our server, You would be prompt to register. Just register with any password you wanted to. After being sent to a lobby you will get the messages says that you're logging in as Cracked id. Don't worry, just change it to premium method so anyone logging on with your username will be authen ticate with Mojang authentication (basically means no one could login with your name except the one that has your Minecraft account) and you will skip the authentication step next time you login and you won't have to /login ever again!