Easy peezy. Head to the booking page here to start with.
For Groupon vouchers select the treatment called ‘Groupon Vouchers’ – you only need to enter the code on the consultation form, NOT the booking page (it won’t be recognised there as it’s Groupon’s code, not mine).
If you have a Gift voucher, just select which treatment you’d like and enter the code from voucher on the booking page to reduce the price.
You will need to complete the booking form at the time of booking.