FHTML5PlatformHttp implementation in UE doesn’t exist - I just tested pull request - https://github.com/EpicGames/UnrealEngine/pull/345 which implements that and it works well - I will be checking in tomorrow in main. Meanwhile you can pull this request in your branch to make IHttpRequest work.
Thanks - I will fix the case!
re: Browser console logging - look for emscripten_log function in the emscripten SDK. you will see it in UE codebase too.
I do think you will run in cross origin issues if the game is not hosted on the same orgin as the uasset - you might have to send headers which allow cross origin on the server which hosts the ussset if its different from the server which hosts the game .js files.