Extensions are usually not available until 3/15 or later so try coming back next week.
Find out more information about filing an extension at the links provided below:
FEDERAL:
https://turbotax.intuit.com/tax-tools/tax-tips/Efile/Filing-an-Income-Tax-Extension/INF12040.html
STATE:
Turbotax could easily add this information to the site and save me these steps.