From Dota 2 Wiki
- Players who purchased a 1.25L Coca-Cola or Sprite bottle with the event logo will receive a Bottlecap Code.
- The Bottlecap Code can be exchanged for an Event Code using the Alipay application for Android or iPhone.
- Select one item from the event page and enter the Event Code to receive a Digital Unlock Code,
- Enter the Digital Unlock Code at the in-game Armory to receive that item.