Want to know why your booking form is asking for a coupon code?
Want to know how to remove it?
The reason a booking form is asking for a coupon code is because you have set up a code which includes this type of service.
If you don't want that option to be included on the form you will need to exclude that appointment type from your coupon code settings.
This could be done simply by not including it in the list of services coupon can apply to, or by excluding it based on price or other factors.