Central bank prints the money, puts it into bank accounts or hosts the bank accounts itself. Government taxes money to destroy it. I think its interesting if you can assign money different "classes" or make it programmable; give fiat away to stoke consumption but make it have an expiration or prevent it from being invested if sourced from a central bank allowance, but lots of hazards too (usual suspects of human governance failure modes). Money earned "human to human" could have a different, higher value or class than money printed for consumption of goods or services that can be produced by automation also comes to mind. Much better imho than the blunt instrument of target interest rates for adjusting the speed of an economy and blanket fiat value.

https://en.wikipedia.org/wiki/Modern_Monetary_Theory