Players could get rewards with KEY, Miner Revenue Card, Gold Card, and other props by inviting friends to play in the game and complete the corresponding tasks in the game. More friends you invited, more rewards you can win.
How to invite friends?
1.Click [My Friends] and [Send Invitation Code] to get your own referral code.
2. Friends you invited to [fill in the invitation code] in the game. After that, the invitation will be completed. And wait for your friends to complete the designated tasks, then you can receive the corresponding rewards on the [My Friends] page.
Each player is allowed to fill in only one invitation code, and cannot be changed after filling in.