You would need to install Windbg Preview from Windows Store
Get it from Get WinDbg Preview – Microsoft Store . If you use the ordinary Windbg that comes wint Windows SDK, this is what you get from trying to open it
Could not find the C:\Users\vimvq\Downloads\core_20211102_090430.dmp Dump File, Win32 error 0n87
The parameter is incorrect.
You also need to install .NET 5 version of sos.
dotnet tool install --global dotnet-sos
and once you used Windbg Preview to open the memory dump, run this command to load it:
.load C:\Users\<your user name>\.dotnet\sos\sos.dll
And now you can start debugging as usual