Your tickets live in your Hardwater account, under My Events. Open the event and you'll find your QR code and mobile pass, ready to be scanned at the door straight from your phone.
You can also pull up your tickets in the Hardwater Events app (or the Hardwater app) on iOS, so you've got them with you even if the signal is patchy at the gate.
If you booked through Hardwater Retreats, your tickets sit alongside the rest of your trip details rather than on their own.