I'd be delighted to get you moving in the right direction with converting from QuickBooks Online to the Mac Desktop version. This transfer will have to happen in two part, first to the Windows version of Desktop, and then from there to Mac. To begin, you can convert your QBO file to Desktop using the instructions below:
Exporting from QBO to Desktop
Start by verifying your Online company meets the Requirements for export detailed at the link here. Once that's verified, also look into the Export limitations to gain a greater understanding of what information can and cannot be converted.
Click the Gear icon ⚙ > Export Data. Under Moving to QuickBooks Desktop?, select Learn more.
Under Download company data, click Learn more.
From this screen, download the Install ActiveX Tool. Once you have, click Get Started or Continue.
Follow the on-screen instructions to export your data. You will eventually be prompted about an email that is to be sent to you with further instructions.
We also offer a comprehensive visual guide on this entire process that I strongly recommend you follow while performing each step. Please know that if you need any additional assistance with this part of the conversion, I'll be waiting and willing to lend a hand from right here.
Once you've successfully converted your QBO company to a Windows Desktop file, you'll need to get in touch with our Phone or Chat Support Teams to make the conversion to Mac. This can be accomplished from the Help (?) menu inside QuickBooks Desktop, as seen in the guide at this link. They'll be able to guide you through the special process necessary to convert your new Desktop file to the Mac version.
Thank you so much for bringing us your question, I look forward to hearing from you again.