Square Appointments: Can my customers use a discount code when booking?

[spruce]

Hello,

I created a discount on all salon services on my website: www.sprucewax.com. However, there is no promo code field that customers can use to apply that discount when they prepay for a service. Is there a workaround for that? I'd like them to be able for them to apply a discount at the time of booking rather than having to discount their services manually when I charge them.

Thanks!

C