how can i e-file 2019 tax return ?

The due date has passed for e-filing an original 2019 federal income tax return. You will have to file by mail if you are filing an original 2019 returns. We suggest sending your return by certified mail with return receipt.

You can e-file an amended tax return prepared with TurboTax. The IRS says, "Only tax year 2019 Forms 1040 and 1040-SR returns can be amended electronically. Please see IR-2020-107 and IR-2020-182 for additional information. You still have the option to submit a paper version of the Form 1040-X and should follow the instructions for preparing and submitting the paper form."

See: Electronic Filing (e-file)

only tax preparers with professional software have the ability to e-file past year returns. the question is do you want to pay their fees just so you can e-file.