Type not found : WebmPlayer

So ive been trying to port a fnf mod to html5 and it says

“source/VideoState2.hx:54: characters 4-30 : Type not found : WebmPlayer”

Hi, @Pancake
could you point to some docs what WebmPlayer is ? as I am not sure I have heard about it inside browser ecosystem.

As I understand it, the WebmPlayer type comes from this extension:

I assume that this extension does not work in the html5 target.