Inside Roblox Voz is implemented as a set of non tradable stats stored per player.
Example fields: - voz_hours_total - voz_hours_building - voz_hours_helping - voz_votes_given - voz_votes_received
These values live in Roblox DataStores and are mirrored to an external Hitchhiker server using HttpService in batched events.
There is no way to trade Voz between players and no way to convert Voz into Robux or any other currency.