You may select the bottom right of the main screen to access the Slots.
Premium Slot is a lottery where you can spend Premium Tickets to obtain rare items. 5 Premium Tickets are required to play once. If you choose to roll more you must use the maximum amount of tickets you have to play (no "in-betweens").
A Collaboration Slot only appears when a collab features. They end on the same date as the collab.
Fashion Accessories Slot
Equip Princess with a stylish accessory at a price of 3 Tickets each roll.
Gold Ticket Slot
Use 5 Gold Tickets to roll a PPS member that you do not have (if you have all of them it will pick random).
Each roll costs 1 Premium Ticket. Comes in the set of 10, 30, or 50 Navi Tickets. (TIP: DO NOT USE THIS)
Use your Friend Tickets (the white ones) to roll for common items and Dress of the Month.