How to Add Friends and Form a Team in MineTogether
Opening the Team Interface
MineTogether is built around a shared team system, so the first thing you need to do is create or join a team. Open the team menu using the keybind the mod adds (check your Controls settings if you have not rebound it). From this screen you can create a new team, give it a name, and become its owner. Once the team exists, you invite other players rather than "adding" them as a separate friends list — team membership is what grants shared access.
Inviting Players
With your team created, use the invite option in the team screen and enter the other player's username. They will receive a request they must accept before they appear on your roster.
Confirming It Worked
After a player accepts, they should show up in your team member list. From that point the team is active in the world: members are recognised as belonging to the same group, which is what enables the cooperative features the mod provides. If someone does not appear, make sure they accepted the invite and that you are both in the same world. Team management (renaming, removing members, leaving) is handled from the same interface.