During scorecard creation, after selecting players and tapping to confirm, you will see the Round setup page. At the top, tap Teams.
After doing so, you can adjust the number of teams, and drag and drop players to arrange the teams however you wish.
Once the teams look correct, you can Customize your round just like you would for a regular singles round. When all the settings look correct, tap Start my round.
Please note, after you've created the scorecard, you will no longer be able to change these teams or add and remove players. Each team's stats will be kept together as a team; by default these stats do not impact your individual player statistics. Teams rounds do not show on course leaderboards.