'tab key not functioning"

I have here the steps on how to manage your invoices in your QuickBooks Online (QBO).

First off, if the Tab key on your keyboard is not functioning, the best workaround I can suggest is to manually click each field so that you can move from different columns in your invoice page. 

However, if the tab key on your keyboard is working, I recommend using a private browser, as it ignores websites from using cookies and doesn’t record any history and data:

• Mozilla Firefox and Microsoft Edge: Press Ctrl + Shift + N
• Google Chrome: Press Ctrl + Shift + N
• Safari: Press Command + Shift + N

If this works, I suggest clearing the browser's cache so the system can start fresh. If you get the same result, I recommend switching to a different supported browser.

Furthermore, I have included some helpful articles that can help you manage your invoices:

• Customise invoices, estimates, and sales receipts in QuickBooks Online.
• Set up and send progress invoices in QuickBooks Online.

If you have questions about managing your invoices or other QuickBooks-related concerns, feel free to drop a comment below, and I'll provide the necessary help.