If you are using a version of TurboTax Online, follow the instructions at the link below.
https://ttlc.intuit.com/questions/1901031-how-do-i-file-an-irs-extension-form-4868-in-turbotax-onlin...
If you are using a desktop version of TurboTax, you have to print and mail the extension (Form 4868). However, you can use TurboTax Easy Extension to file an extension online.
See https://turbotax.intuit.com/irs-tax-extensions/
