Configuration of emscripten compiler on Windows

[Montjet]

Hi,
I just downloaded Qt 5.13.1 with QtCreator 4.10 and I want to compile example solution to web using emscripten on Windows OS.
It looks that emscripten works perfectly (console detects em++) but I don't know how to configure QtCreator.

My configuration of C++ compiler:

Kits:

Issues:

:-1: warning: "D:\IT\mingw-w64\x86_64-8.1.0-posix-seh-rt_v6-rev0\mingw64\bin\gcc.exe" is used by qmake, but "D:\IT\emsdk\emscripten\1.38.30\emcc.bat" is configured in the kit.
Please update your kit (Qt 5.13.1 WebAssembly) or choose a mkspec for qmake that matches your target environment better.
:-1: warning: "D:\IT\mingw-w64\x86_64-8.1.0-posix-seh-rt_v6-rev0\mingw64\bin\g++.exe" is used by qmake, but "D:\IT\emsdk\emscripten\1.38.30\em++.bat" is configured in the kit.
Please update your kit (Qt 5.13.1 WebAssembly) or choose a mkspec for qmake that matches your target environment better.

Emscripten v1.38.30x64
Qt v5.13.1
QtCreator v4.10

How should I configure this compiler?

[lorn.potter]

I tried this on windows and it seems QtCreator will not accept wasm-emscripten mkspec at the kit level. But the QtCreator preview does.