Thanks for choosing QuickBooks. 

I appreciate you for bringing up this concern.

You'll want to manually configure your firewall to allow QuickBooks from running. 

Please follow the steps found in the article below (scroll-down to Manually configure exceptions and ports to your Firewall):

Configure Firewall and Internet security settings for QuickBooks Desktop.

However, if you're still unable to add QuickBooks after performing all the troubleshooting steps and , I recomment contacting our support team so they can provide you additional steps on how to successfully add QuickBooks. They also have the tools to pull up your account in a secure environment.

For future reference, you can check these help articles for more information: Account Management.

Please let me know if you need anything else. I'll always be here to help.