Thanks for coming back for more support, @marcia9. I can feel what you've gone through with the Intuit Developer phone support team. I'm here to help ensure you're able to link your amazon in the QuickBooks Self-Employed Labs successfully. 

You've mentioned that you've disabled the two steps verification. I'd recommend you turn it on again for your amazon account to get it to work. That way, you could enter the code texted to you instead of typing the numbers or letters you see.

Should this be the same issue, I'd recommend reaching out to our QuickBooks Self-Employed Support team to help you identify the cause of the issue. They can assist you in creating a case to investigate this behavior and check it with our engineers.

For future reference, read through this article and learn about how to create rules to speed up reviews in QuickBooks Self-Employed. 

I'm always here to help should you have additional concerns. Take care.