TurboTax Easy Extension will be available on March 18th:
https://ttlc.intuit.com/replies/3301328
Once the Easy Extension option is available on March 18th, follow these steps to request an extension:
- Sign in to your TurboTax Online account
- Click on "Search" next to the magnifying glass in the top right
- In the search box that appears, type "extend" and press return
- Click the "Jump to" link that appears and follow the instructions
If you want to file prior to that date, you can paper file by using Form 4868:
https://ttlc.intuit.com/replies/3301811
The deadline to file a tax extension is April 18th, so you can file for an extension at any time until that date.