Packages and vouchers yes, memberships not yet
A course of treatments is sold at your desk and counted down by the system: sessions used, sessions left, a canceled appointment giving its session back, and the price frozen at the sale so a rise later never changes what somebody already bought. See courses and packages.
Gift vouchers are sold at your desk or on your website through your spa's own Stripe account, and they are spendable across several visits rather than used up all at once. A treatment can also carry a deposit that clients pay on Stripe's secure page when they book, with the rest paid at the spa.
What Velvet Lead still doesn't do is memberships or recurring billing. A course is paid for once, not monthly. You can describe a membership program in your FAQs or on your pricing page so the assistant can explain it, but sign-ups and billing stay with the system you use today. If memberships are the center of your business model, tell us on the demo call so we can give you a straight answer before you commit.