Approach is based on this [forum thread](https://forum.qt.io/topic/133002/qt-creator-6-0-1-and-qt-6-2-2-running-on-windows-7/60) but better: many improvements amongst important fallbacks to default Qt 6 behaviour when running on newer Windows.
You can use [our prebuild binaries](https://github.com/crystalidea/qt6windows7/releases) (we used Visual C++ 2019 with OpenSSL 1.1.1k statically linked, see [compile_win.pl](https://github.com/crystalidea/qt-build-tools/tree/master/6.6.1) script) or compile Qt yourself.