Hi there,

If you mean coins, you c*e them for functions like group donations, equipment strenghtening, 8 Inner Gates system, etc.
If your intent was to ask for ingots, those are a virtual currency in game that you can get by recharging (purchasing it for real money). It can be used to buy many items in game, as well to participate in many events. Most uses for it are also covered by coupons, but there are some ingots-exclusive functions :)