Treatment Add-Ons let you attach supplementary services to a base treatment, adding time, cost, and detail to an appointment without creating a separate booking. They're designed for services that complement what a practitioner is already providing in a single session, like adding cupping to an acupuncture appointment or exosomes to a microneedling session. They block off additional time for the same practitioner and appear as a separate line item on the patient's invoice.
Treatment Add-Ons aren't intended for treatments that span different disciplines or practitioners, or for products a patient purchases and takes home (use Products instead).