Can i add my OWN features to UE4

Because there are Some features that i miss.

Yup, here’s a related answer:

pff, just realised that you’ve asked the question I just linked to. I don’t get it then… you’ve already received your answer, no?

am sorry.

i mean a extra feature like that i can run unreal engine on the browser or someting like that.

run unreal engine on the browser or
someting like that

But it’s already possible:

I Mean controle my game on the website

Playing the game in the browser?

I Mean controle my game on the website

no, i mean that i can update my game without to download it ( the Unreal Engine ).

You mean something like this: https://forums.unrealengine.com/community/general-discussion/1743005-work-from-home-how-to-use-unreal-through-remote-desktop

so i can change the source code and put that source code back in Unreal engine and make my own feature

no, i mean that my i can use the enigne without downloading / installing so that i can control my game in my school to.