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You can share your Gift Code to other players, and you can enter the Gift Code you received from other players as well. Please check out the following tips.
1. When entering the Gift Code you received from others:
You can receive Reward in mailbox three days after registered. You can ONLY enter Gift Code once.
2. When sharing you Gift Code to others:
You can give out Gift Code to other players 5 times every week, but you can ONLY claim the rewards from the Gift Code once.