Sorry you need 10.14 to install it. Or find another computer. Or you can use the Online version.
Call in for a refund. When you fill out the from use the word BILLING ISSUES instead of the word “refund.” Contact Customer Service 5am-9pm Pacific time 7 days a week, https://support.turbotax.intuit.com/contact
If you can't install Turbo Tax Desktop program you can transfer from your 2019 return from your computer into the online version. You need to have the file ending in.tax2019 on your computer.
If you used the Desktop program last year here’s How to transfer into the Online version, expand the blue link if you used the CD/download last year
https://ttlc.intuit.com/community/entering-importing/help/how-do-i-transfer-last-year-s-return-into-...
If you used the Desktop program before you may notice several differences and not like the online version. It has less features and no Forms Mode. You can only do 1 return. Your return is only saved online so be sure to save both the .tax2020 data file and the pdf file to your computer when you are done. In case you need to amend in the future or if you need a copy to get a loan or something. You might not be able to access your online return when you need a copy.
Start an Online return here,
https://turbotax.intuit.com/personal-taxes/online/
