Intergrating MAC online payroll with Quickbooks DESKTOP for MAC.

No it will not, desktop (Win & Mac) have a different payroll service you need to use the desktop payroll service.  Or an outside payroll service that will send an export that you can import

Hey there, @BSILP. 

I'm so glad to see a new face here in the Community. I appreciate you coming to this platform with your question about merging some data. 

Based on the info provided, sounds like you haven't used our payroll prior. With that being said, you should be good to go ahead and purchase payroll if you're using a supported version of MAC. Here's how: 

1. Go to the Employees menu. 
2. Choose Add Payroll. 
3. Hit Try it Now to create a payroll account. 
4. Press the To Do tab. 
5. If you haven’t already, select Complete Setup. If you’re ready to process payroll, select Run your first payroll.

Click this link for more details about setting up your payroll. 

Now, you'll be able to successfully have a payroll account and get back to running your business. It's always my priority that you're taken care. Don't hesitate to ask if you have any other questions or concerns. Bye for now!