Treatments can be based and invoiced on a number of materials that are being used, like Botulinum Toxin or a dermal filler. On the other hand, a treatment could be based on a price and the used materials like e.g., during small surgery do not result in a treatment price (e.g., a blepharoplasty has a certain price-tag regardless if you use 1-2 or 3 cloths during surgery).
To add a treatment, open record settings > treatment . Click the plus (+) icon in the right upper corner.
Choose whether you want to add a treatment based on material usage (e.g. a Botulinum Toxin treatment) or a treatment with a certain price disregarding how many materials or products are used during the procedure (e.g. a Peeling or eyelid surgery).