Cost of using cash item cabinet

[Smoker]

Hello!
Can anyone help me where to look for the solution to the following error?

The cashitemkabinet is currently free to use, I would like it to deduct moonstones.

Thanks if you read and for any replies.

 

[Jineman]

long time i don't have looking for 4Story files, but maybe you can check cashcabinet... function on db, and search the using of this function on source