Windows 10: IE11 on Windows11 required, institutions old services

I'm having a complicated issue which might also affect other people/companies in different countries. In my country, Romania, one of the institutions for tax handling, has a deprecated IE working only system, on where you login via IE through a certificate you registered with them. The thing is that no other browser has ever worked and of course nor does Edge with IE compatibility work.So the situation is as follows for me - I can't update to windows11 because that would make communication via that site impossible. At the same time from what I read IE might be removed from Windows10 as well in

:)

 

long runnig script error when using Office 365 (WIN10/IE11)

I tried everything on the list here with the exception of checking for the latest IE11 service pack. The article only had instructions for IE11 on my Windows 7. How do I check for IE11 on Windows 10.
None of the other steps have improved my situation.

 

The browser you are using is not supported (IE11 required, but I AM using IE11!)

I have a Win 10 PC w/IE11 that has an issue. When I access certain sites that require certain newer versions of IE, the sites are throwing errors that my broswer is not supported. They require IE11 - which I am running.

The sites are not in the compatability view list, but the sites just aren't recognizing that I'm using IE 11.

I have other Win 10 PCs that were from the same image, and they don't have this issue accessing the same sites. Is there a setting or something that is causing sites not to recognize that I'm using IE11 on this one PC?

 

如何升级windows11

我需要升级windows11的教程，请使用中文答复我，谢谢