To invite your friend, please follow the steps below:
1. while in the lobby, press X to bring up the friend list
2. Once you bring up the friend list, scroll between the players in your friend list and press Y to invite them to your Team.
3. In case you want to invite a friend not in your friend list or is on PS4, press the View button that would bring up the Nickname search menu. Enter the players nickname and then invite them to your team