If you booked with US...

Log into your Dividend Miles account.
• Click on Account Information (left column of right box near the top)
• Scroll down to the bottom of the page to Other Info.
• Enter Redress and Known Traveller boxes.

If you booked on another airline, make sure your KTN is in your profile with that airline's system. It should transfer depending on the airline. AA's is one that does.