How to initialize WebGL2 Context with OffscreenCanvas

I'm going to do some work in a web worker so that I can not have a `canvas` element on the DOM tree. However, `emscripten_webgl_create_context` api requires an id attached to a canvas in the DOM tree. I know I can create a canvas object by `document.createElement('canvas')` then transfer this canvas to offscreen. But still, how can I pass this offscreen canvas context to wasm?

In a nutshell, how can I create a WebGL2RenderingContext with emscripten ?

Thanks a lot for your patience.