You cannot fix it. If you cannot upgrade your OS to meet the system requirements to use desktop software then your option is to use online TurboTax software instead. If you purchased the 2024 desktop download, seek a refund for the purchase and use online this year. You cannot pay for online by using the license key.
https://ttlc.intuit.com/community/system-requirements/help/minimum-system-requirements-for-turbotax-mac-software/00/25609
To request a refund for a TT product
https://ttlc.intuit.com/turbotax-support/en-us/help-article/intuit-refunds/request-refund-turbotax-product/L834M6uyW_US_en_US?uid=m6meybc2