I was on longterm disability last year. did not receive a w2 . how do i file

It depends on what type of disability income this was.  And it’s possible that you don’t even need to file a return, if this was your only income.  

Please see the TurboTax Help article Is disability income taxable? and the links at the bottom of that page for more information.

The TurboTax Help article Do I need to file a federal return this year? is  also helpful.

If these links aren’t helpful, please provide more information on the type of disability you’re getting.