Simple and clear: open the article from Google, copy the key shown in that article (we shown an image too), paste key here and verify.
Click Get Key Button. A new tab will open with Google search results. Open the top article result we point to — inside that article (look for the red box) you will find a short code labeled "Your Key". Copy that exact code.
Come back to this tab and paste the copied Key into the box below exactly as it appears (no extra spaces).
Click Verify. If the Key is correct the steps will hide and the destination link already on this page will be shown.