>>509413675 (OP)Why do you need money?
This question itself is deceptive.
Paper money is worthless, nobody needs money.
You can improve the question by saying:
What do you need money for?
you exchange x for money
then you give the money in exchange for y
In Star Trek, while the Federation exists in a post-scarcity society with abundant resources, they still utilize a form of currency called "Federation Credits".
In the Star Trek episode "The Trouble with Tribbles," The tribbles were being sold by Cyrano Jones, who stated he was selling them for 6 credits each, with a 10% profit, making the selling price 6.6 credits
On Deneb V, Harry Mudd faced multiple death penalty options for fraud.