When you sign up for a free trial of one of our paid plans, like many other merchants, we validate your eligibility for a subscription through your payment method.
Rest assured that if you cancel your subscription at least a day before the end of the trial, you will not be charged. You can even request that your payment method be deleted from our system following the cancellation.
I hope this clarifies it. Please let me know if there's anything else I can help with.