Allow me to give some clarification on transferring your company file from QuickBooks Desktop (QBDT) to QuickBooks Online (QBO), BaylightContracting.
 

As stated by my colleague, we discontinued offering QuickBooks Desktop for Mac as it no longer aligns with the company's goal or market demands.
 

However, as a workaround, you can look for a third-party migration tool to convert your company file from Mac to Windows since you have an active subscription on your QuickBooks desktop for Windows. From there, you can work on your windows computer to initiate a migration once the file is converted.
 

Additionally, I suggest reaching out to our QuickBooks Desktop support team for more help with this issue, especially since you're unable to access your company file.
 

Should you require further assistance about transferring company files on QBDT, please don't hesitate to reply. The Community is always here to lend a hand.