Web UI (HTML/CSS/JS Interface Widgets)

Well if you can read C++ then you must have missed this…

https://github.com/tracerinteractive/UnrealEngine/blob/4.26/Engine/Plugins/Runtime/WebUI/Source/WebUI/Private/WebInterface.cpp#L224-L238

But alright, I’ll add a section to the documentation in the next update about how to enable IME support (cause you assumed everyone in the world uses IME and wants it enabled by default).