You could use one of the TurboTax 2017 desktop editions to amend the tax return, but it would not be easy since the original return was not completed and filed using TurboTax.
What you would have to do is purchase, download and install on a personal computer one of the 2017 desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
Then enter the tax data from the 2017 tax return Exactly as filed into the 2017 desktop program, to include any errors and/or omissions. Then in the File section of the program indicate to the program that you are printing the tax return for mailing. Save the tax return as a PDF for mailing which will fool the software into believing the return was filed.
After the 2017 return was completed and "Filed" you could then go through the amend procedure with the 2017 software.
See this TurboTax support FAQ for amending a 2017 tax return when using the desktop editions - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-return-in-the-turbotax-cd-download...
