You can use the TurboTax online editions for the 2020 tax return with your current Mac OS - https://turbotax.intuit.com/personal-taxes/online/
If you already purchased the TurboTax desktop software -
Go to this TurboTax website to request a refund for the software purchased from TurboTax - https://support.turbotax.intuit.com/forms/refund-request.jsp
Use this TurboTax website to check your orders and payments -
https://turbotax.intuit.com/personal-taxes/cd-download/order-status/
