Follow the steps below to authorize with QuickBooks and connect to a company file when both QuickBooks and the add-in are running on your local machine.

1. Open QuickBooks as an administrator and open the company file you want to connect to.
2. Connect to QuickBooks. A dialog will appear in QuickBooks prompting you to authorize the add-in. After granting access to the add-in, you can now execute commands to QuickBooks.

3. If you want to connect to the company file when QuickBooks is closed, set the CompanyFile connection option when you execute commands. QuickBooks will open automatically in the background with the file specified.

   Note that if QuickBooks is open through the application UI, only that CompanyFile can be used.