1.12.1 Help-How to change vendor currency

[EEnope]

Hello,

How do I change the currency usage of a custom vendor ( I want to be able to assign unique currency to players for rewards when completing things such as boss kills and winning/participating in a bg) And I would like to assign warsong gulch marks as the server currency, to be able to buy stuff from vendors as a way to acquire items also (I would like to be able assign random loot boxes to BG wins and boss drops)


Basically the main question is here, how can I assign a currency to a vendor and how can I assign a certain cost to items in a vendor!

Many thanks

EEnope