After Download the datapack, move it into the folder "datapacks" in your world folder.
Register with:
/trigger register set <password>
Login with:
/trigger login set <your password>
Change password with (you need to be logged):
/trigger changepassword set <new password>
To see te settings menu use te command:
/function auth:settings
To give a authentication bypass to a player use te command:
/tag <player> add auth.bypass
and to remove it, use:
/tag <player> remove auth.bypass