To sign up for TTT, select "Team" in the first dropdown. Next in Team Name field, you may enter your team name or use back slashes to separate each team member's last name, such as Smith/Jones/etc. Lastly, in Select Distance dropdown, pick "6 Laps - 40K TTT". There's no 20K TTT option.
All 40K races must pre reg. Same day registrations only available for 20K's.
Hope to see you there: http://www.webscorer.com/fitt?pg=register