I have been struggling trying to get this to work as well for the past couple of weeks.
I’ve been trying out this community-supported HTML5 platform plugin which has probably gotten me the closest. I was able to export a working html5 game, as well as open a dedicated server. But I have yet to actually be able to connect to a dedicated server in the HTML5 game. But I think with enough patience one would hopefully be able to eventually get it working!