I have QB online. I am trying to look at a qbb file sent from my partner in another business. Can't get it to open. Need help.

I can help you open your file, robert48. 

The QBB file is a QuickBooks Desktop backup file. We'll restore that file in the Desktop version using our trial links. From there, we can export the data from the desktop version and import them into your QB online account. 

Here's how to easily export the file:

1. Restore the backup copy. 
2. From the Company menu, choose Export Company File to QuickBooks Online. 
3. Confirm and follow the prompts to connect to the Online version. 

I'm here to assist you if you need more help. Have a nice day!

@robert48 

QBO and QBD are two different platform. Open your QBB file on trial license of Pro 2020.