money is not created by the act of exchange.
money is different from barter, but also from credit.
an act of bidirectional exchange is barter and comes with its own problems.
an exchanfe where just one side provides is a donation or a credit/loan
That is different too. a credit/loan has to be settled later on.
you use either goods (as in barter) or money to settle it.
So paying money is used to SETTLE debt 🙂