Well if you just printed Star Trek money, they wouldn't have to spock their fivers! Come on now!
The federation doesn't have money the have solved the scarcity problem
Not the federation latnium is used by non federation worlds and occasionally by fed when dealing with non fed people but nobody in the fed uses it
Im not sure they ever explicitly said it, or at least not in the Roddenberry era.
While money may not exist on Earth or the core worlds (or the entire federation) per se, there still are Federation credits for use on non-federation worlds. So maybe like on Ferenginar (if it can convert into Latinum) Qo'noS (if they have money), Romulus, or any other economy. So while he may not of used money (as he only bought from Federation worlds), there still is money. Also the existence of the bank of Bolarus seems to imply there is a currency for the federation (credits).
While money may not exist on Earth or the core worlds (or the entire federation) per se, there still are Federation credits for use on non-federation worlds, space stations near independent powers, and for commerce with other independent nations (like the negotiations for the Barzan Wormhole). So maybe like on Ferenginar (if it can convert into Latinum) Qo'noS (if they have money), Romulus, or any other economy. So while he may not of used money (as he only bought from Federation worlds), there still is money. It also can be used for worlds which have not made the transition to a post-scarcity/money environment. And to add to that, the Bank of Bolarus implies that some money is used by the federation. So while you are right in that citizens of the federation probably get stuff for free, that doesn't mean money doesn't necessarily exist (which you did point out.)
This is one of the most funny bank recommendations I have seen in a long time
Bank of Canada urges
I'm gonna go with "Bank of Canada doesn't actually give a shit and just released a boiler plate statement about defacing currency."
So apparently in Canada it's actually illegal to deface currency. Like the act itself is a crime with a prison term. It's not like the US where it's only illegal if you do it for the purpose of fraud.
https://www.leicestershirevillages.com/the-legal-implications-of-cutting-money-in-canada-uncovering-the-consequences-of-defacing-canadian-currency/
Which is a fucking stupid law if you ask me, as a Canadian.