To send a discounted service to customers, you'll have to copy the service you wish to have a discount for. So in your business > services > copy service.
You can then edit the service so that it shows that there is an offer on it. On the new service > pencil icon to edit > edit duration > add offer:
Which will then display like this:
Make sure to set this service as "Not visible online"
Now you only have to create the widget, which will act as a type of discount code.
Go to booking tools > booking widgets > create new widget > give it a name > filter by service > choose the new discounted service you created > save widget > get the widget URL.
This service won't show on your microsite or other booking tools and will only be available to people with the link😊