You can complete a Form 4852, Substitute for Form W-2, Wage and Tax Statement. To do so in TurboTax see the following: How do I file a substitute W-2 using Form 4852?
IRS says:
if you do not get W-2 by Feb 14, contact IRS by phone with employer information.
They will tell you how to proceed.
Turbo Tax does not have a copy of your W-2, but your employer may provide it.
If the W-2 is not available, here are the steps to take to get your W-2.
To import your W-2 you will have to have some confirming information.