To request a refund for a TT product
https://ttlc.intuit.com/turbotax-support/en-us/help-article/intuit-refunds/request-refund-turbotax-p...
Since your Mac does not meet the system requirements for desktop software, you can still use online if you want to use TurboTax. You cannot pay for online with that license key.
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.**