If the OUTPUT_NAME of a target is changed like this:

qt_add_executable( App MANUAL_FINALIZATION qml.qrc )
set_target_properties( App PROPERTIES OUTPUT_NAME "RenamedApp" )

qt_import_qml_plugins( App )
qt_finalize_executable( App )

The wasm and js file are named RenamedApp.js + RenamedApp.wasm.

But the html file is named App.html and it loads: qtLoader.loadEmscriptenModule("App");

If you need a complete example project please write me.