What's the use of a copper coin in the mainland?

If you have universal gold coins on you (that is, you can open the gold coins in the bottom row of your backpack and buy and sell them with the players), then you can throw them away.

This copper plate is equivalent to 1 copper of ordinary currency. In the future, there will be a task that requires you to give 1 copper NPC currency, so if you haven't earned any currency by this time, then this copper coin will come in handy. As long as this is in the bag, the task is completed by default.

I threw it, dug a grass outside, went back to the booth where the players concentrated, found a grass collector to sell it to him, and easily got 1 silver. Why do you still have this copper coin? Even if you are really copper, you can't make money. Just leave one in the warehouse.