Given that this is now 2022, the problem is that the IRS no longer will accept an electronic filing for 2019 using TurboTax nor an amending of a 2019 filing. You will need to file the amendment in printed form and mail it in. Alternatively, you may use the services of a professional account with the appropriate professional tax filing software (not TurboTax or other comparable retail programs).
You can obtain a copy of the 2019 TurboTax from other online sources and if you have the .TAX file from the original 2019 filing stored on your MAC, you can create a printed amendment instead of doing it manually.
The deadline for filing an amended 2019 return for purposes of obtaining a refund or additional refund is April 15, 2023, so if the intent in filing the amended return was to obtain a refund, it it must be sone by April 15, 2023. The IRS will only process such a request within 3 years of the original filing deadline.