They give a 30-day free trial, it seems (last item in the 5-reasons list):
"Triplicate has no demo version, but I do offer a 30-day return option: if the fonts aren’t your style, you can cancel your license for a refund."
"Triplicate has no demo version, but I do offer a 30-day return option: if the fonts aren’t your style, you can cancel your license for a refund."