Virtual keyboard crash when I try to select input methods(chinese, english etc) on browser

When I try to select input methods from browser(scroll the comboBox, from english to chinese), the app crash and show following message

Error message :

Application exit (To use dlopen, you need to use Emscripten's linking support, see https://github.com/emscripten-core/emscripten/wiki/Linking)

I add following commands

static{ QTPLUGIN += qtvirtualkeyboardplugin QT += svg }

Do not work, then try

wasm { QTPLUGIN += qtvirtualkeyboardplugin QT += svg }

Do not work either. What do I missed? How could I make the virtual keyboard work?
Is it possible to trigger virtual keyboards? From technical view points