A .qbb file can only be opened on a QuickBooks Desktop version, regent12.
If you're migrating to QuickBooks Online, the file can be imported to your account using Odyssey. It's an accredited third-party application that offers moving data from QuickBooks Desktop to QBO. Here's the link: https://www.odyssey-resources.com/quickbooks_online/Conversion.php.
Let me also share these support articles for more insights about data conversions:
I'll be around if you need more help. Thanks!