in Which browser can I use "dispatchevent" in the background tab?

I tried dispatchEvent in the background in chrome, but it didn't work. When i try it in firefox, It worked delayed.

I'm trying in the same code firefox slow running chrome also does not work, I think this is browser-related.

How do I revoke these restrictions on browsers? or can you recommend a browser without restrictions?

.

coordX = 100 // Moving from the left side of the screen
 coordY = 100 // Moving in the center


    // Create new mouse event
     ev = new MouseEvent("mousemove", {
        view: window,
        bubbles: true,
        cancelable: true,
        clientX: coordX,
        clientY: coordY
    });
window.document.querySelector('#canvas').dispatchEvent(ev);

from in Which browser can I use "dispatchevent" in the background tab?