What do you mean you cannot sign your file? A tax return is only physically signed in ink if is being printed and mailed to the IRS or to a state.
Or are you referring to e-filing your tax return with an electronic signature? Your electronic signature on a 2019 tax return is the 2018 AGI reported on the 2018 federal tax return that you filed. If you did not file a 2018 federal tax return or filed the 2018 return late in 2019 then enter a 0 (zero) for the 2018 AGI.
Or are you referring to not being able to e-file at this time? That is probably caused by one of the forms or schedules included in your tax return not being finalized for filing. Click on the Review tab and the availability dates will be shown.
