If you used the 2021 program it would have told you if your system would not be enough for the 2022 version ... note the chart for prior tax years ... it goes up one level each year so 10.16 or later would be expected. 

Operating System

• 2021: macOS Catalina 10.15 or later
• 2020: macOS Mojave 10.14 or later
• 2019: macOS High Sierra 10.13 or later
• 2018: macOS X v.10.12 or later (64-bit required)