You need to claim the server in order to prove that you are an administrator of the server. Claiming the server page gives you options to manage parts of the page.

Steps

1. Visit your server page and click the link near the map image (to the left of it) named "(claim server)" or "None - Claim Now!"
2. Find the "Claim Ownership" button.
3. To the right of the button, you will see a (?) button you can click to get instructions on how to do this.

Notes

Once you claim it, there will be a "Manage" link on the server page in the sub-menu above the map image or on your favorite servers page http://www.gametracker.com/servers/.

There is currently a 7 day delay from the time you register to the time you can claim a server page.