How to remove contextmenu event without using getEventListeners() in bookmarklet...

Question 1

I've got a piece of code which successfully removes the block on right-clicking
I need to make it work in Chrome only so getEventListeners() is fine
I can't install my own extensions
I have code which works in the Console, but it doesn't work in a bookmarklet, telling me that getEventListeners() is not defined

Is there any way around this? Clearly a bookmarklet runs with a slightly different Javascript engine from the one in the Console.

Question 2

getEventListeners() is a DevTools-only function. It isn't available to normal page JavaScript, so a bookmarklet can not use it.

If the goal is just to re-enable right click you can usually bypass the site's handler instead.

document.oncontextmenu = null;

window.addEventListener(
 "contextmenu",
 event => event.stopImmediatePropagation(),
 true
);

or as a bookmarklet:

javascript:(()=>{document.oncontextmenu=null;window.addEventListener("contextmenu",event=>event.stopImmediatePropagation(),true)})()

That should work on most sites. There is no reliable bookmarklet API for listing or removing every listener added with addEventListener(). You would need DevTools or an extension for that.