Allow me to introduce myself. I am Hexachlorophene J. Goodfortune, Kidnapper-At-Large, and Devourer of Tortoises par Excellence, at your service.
If you can read this, then this sentence is false.
How do I put coins on pottery? Must I spend a resource (any kind) in my city management to do so?
The "?" icon means any resource, and there are 2 of them, so you may spend any two resources during city management to put a coin on pottery (once per turn, of course).