Welcome to Community! It's important that you're able to access your QuickBooks account on your Mac, so you can get back to business as soon as possible. I'd be happy to provide more information so you're on the right track!
Based on the information you've provided, I recommend updating your QuickBooks account to the newest version. Should you need additional assistance, please don't hesitate to contact us.
Schedule a Callback or start a Chat: click (?) Help in the upper right in QuickBooks Online > enter "Contact support" > hit Contact Us > provide a brief summary of your situation > hit Let's Talk > choose Get a callback or Start a Chat. Social Media: Facebook, Twitter, and Instagram. Support hours are from Monday to Friday between 9 a.m. and 8 p.m. ET.
Please feel free to reach back out with other questions. We'd be glad to assist!