You have to have the W-2 in order to import it into TurboTax. For security you have to enter some information from the W-2 in order to import it into TurboTax. TurboTax can't access it without that information.
Your employer is required to give you the W-2. If they do not make it available to you online they have to mail it to you. So make sure they have your current address now, before they start mailing out W-2s.