Click on the next button. "Setup Interconnected Wallet" Select the months that are on your voucher. Now enter your code in the provided field. You have successfully used your voucher. If you don't have a voucher, you can also buy an interconnected wallet. (ICW) Remember, you get more info need 550 more Minebase tokens in your wallet for each interconnected wallet.
For 1 ICW you need 1.100 Tokens, For 2 IWC you need 1.650 Token. For 3 IWC you need 2.200 Tokens For 4 IWC you need 2250 Tokens and for 5 IWC you need 3.300 Token on your Wallet.