New online quickbooks payroll is not syncing with my online payroll for mac.

Welcome to the QuickBooks Community, Steve!

Recently, IOP is moved to a standalone QBO Payroll, and other QuickBooks for Mac users are also asking how to sync or import data from the new payroll to QB for Mac. Given these scenarios, I think your concern is more on reflecting your payroll transactions into QB Mac and not into the online payroll (IOP) in QB MAC. By the way, the latter is not possible.

Currently, you'll want to export your payroll data via an IIF file while the option to sync QBOP and QB Mac is not available. I'll guide you through the steps.

First, set your export preference in QBO Payroll to QuickBooks Desktop for Mac and then generate the IIF file.

1. Click the Gear icon and select Payroll Settings.
2. In the Export section, click the Pencil icon on the right.
3. On the Export preferences page, choose QuickBooks Desktop for Mac.
   
4. Select Continue in the lower-right corner.
5. Review the assigned accounts and click Done.
6. In the Export section, click on Export transactions. This option appears after changing the setting.
   
7. Click OK. This will download the IIF file to your computer.

Second, import the downloaded IIF file into QuickBooks for Mac.

1. Back up your company file. 
2. Once finished, go to the File menu.
3. Select Import.
4. Click From IIF Files, choose the downloaded IIF file.

Let me know if you require further assistance. I just want to make sure that you're able to successfully follow the steps, so you can focus on other matters in your business.