What years? You can ask support.Contact Customer Service You need to pick the CD/Download program in the product drop down box.
5am-5pm Pacific Time Monday -Friday
https://support.turbotax.intuit.com/contact/
What is the Turbo Tax phone number
https://ttlc.intuit.com/community/using-turbotax/help/what-is-the-turbotax-phone-number/00/25632
You can try downloading the amend programs. I assume you still have the .tax files?
2018 Amend programs
https://turbotax.intuit.com/personal-taxes/cd-download/amend/ty18
2017 Amend program
https://turbotax.intuit.com/personal-taxes/cd-download/amend/ty17/
