Microsoft just released this:  

Today we announced that the future of Internet Explorer on Windows 10 is in Microsoft Edge. Internet Explorer mode (IE mode) provides legacy browser support within Microsoft Edge. Because of this, the IE11 desktop application will be retired on June 15, 2022. This means that the IE11 desktop application will no longer be supported and afterwards will redirect to Microsoft Edge if a user tries to access it.

Internet Explorer 11 desktop application

• Timing: The IE11 desktop application retires on June 15, 2022
  • Windows 10 LTSC and Server not affected. For a full list of what is in scope for retirement, see the FAQ.
• Action:
  • To continue using a supported browser, transition to the new Microsoft Edge.
  • To continue using legacy IE-based sites and apps, you will need to configure those sites and apps to open in Microsoft Edge using Internet Explorer mode.

Is QuickBooks going to provide an option to reconfigure itself to allow us to run Edge in Internet Explorer mode?  

They need to fix this ASAP.  This is a serious problem.