This is a very simple puzzle that just requests from you that you approve some tokens for the staking contract, so you can stake them. After staking them, click again on Approve and make sure to approve the staking contract for 0 tokens (this can be done directly in Metamask by editing the approval settings). This can also be done by using this tool by Etherscan.
Once you've deapproved the tokens, you can click on Verify Your Smartness for the page to tell you that you are indeed Smart!