First of all, go to https://ico.let.bet and follow the below instructtion:
Once you already had an account, go to your wallet detail page by selecting [Main] - [Wallet] in the left-side menu.
- In the session of LBT wallet, click the [Update Wallet] button update your wallet's address. ( LBT Wallet session is the 3rd session)
- Now,there is a popup where you can enter the address. Then, hit the [Update] button to apply the change.