According to what you wrote, you use Godot in version 4.0 beta 3.
If that's true I'm even surprised, that you managed to build it.
Godot 4.0 have yet no support for export to web (HTML5).
Export template does not exist yet. If you really need Web export, you stuck with Godot 3.5 for now. Sorry :(
I too have a project in Vulkan that's waiting for Web support.