Credit scores aren’t a direct result of currency. Credit scores are the result of lending and credit, which is possible without currency.

Example: “I could give you this car if you promised to bring me schwiftyfive thousand sheep over five years, but according to my records you’re only good for schiftytwo sheep. Sorry pal. Here, first borrow this chicken, and give me an egg every day for a few years to prove that you’re the kind of guy/gal/ghoul who honors debts, and we can discuss the matter again.”