@vickysteeves I believe a Loyalty Program is what you want to search for. Often they're integrated into the existing point of sale system.
In this area, "Free" usually means that the host company finds value by invasively tracking customers. Just something to keep in mind.
My info is a bit out of date, but here are 2 suggestions:
https://loyalty.whisqr.com/ (There's a fee to print cards, but you can do it yourself.)
https://loyverse.com/loyalty-program (Part of a full suite of business management tools)
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