Sorry---if you cannot upgrade your OS you will not be able to use the desktop download. But you can still use online software. Seek a refund for the download. You cannot use the license key to pay for the online software.
https://ttlc.intuit.com/community/system-requirements/help/minimum-system-requirements-for-turbotax-...
To request a refund for a TT product
https://ttlc.intuit.com/turbotax-support/en-us/help-article/intuit-refunds/request-refund-turbotax-p...
ONLINE 2024
https://turbotax.intuit.com/personal-taxes/online/
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
