Modern Warfare and Warzone COD Points is an in-game currency that's used for purchasing the Battle Pass or items in the Store.
In order to use your collected Sea Treasure Tokens, you'll need to head to one of the four petrol stations on Ashika Island. There will be vending machines inside these buildings, and upon interacting with them, some random loot will be dispensed at the cost of 1 Sea Treasure Token.
