Yes. Open the game, tap Add a friend, enter their first name, last name and phone number, and pay for their spot alongside yours. You can add as many friends as there are open spots. They don't need the app or an account.
Everyone who plays needs a spot on the roster and must be 18 or over.
Friend can't make it? Tap Manage spots, then the trash icon next to their name, then Remove. The same 24-hour cancellation deadline applies.