Below are the requirements I found for the Mac version (posted 12/10/18). You can also run the PC version if you also have Windows installed on your Mac. Some people find it more stable and more users available for support.
QuickBooks for Mac 2019 (applies to US only)
Minimum system requirements
At least macOS 10.12 (Sierra); supported by macOS 10.13 (High Sierra), macOS 10.14 (Mojave)
Intel processor, Core 2 Duo or higher
Multiuser Server: Intel Core 2 Duo or higher processor to run server
2 GB RAM (4 GB RAM recommended)
250 MB of available disk space
CD/DVD drive or Internet connection for downloaded installation
Printer: 100% Macintosh-compatible printer, if you plan to print invoices, checks, deposit slips, lists, purchase orders, mailing labels, reports, or graphs
Checks: Use Intuit Checks if you plan to print checks. Canadian Image Ready Checks are not supported
