How to avoid input keyboard shortcut stealing by websites in chrome extension develpment

I'm working on browser extension development and insert an input form in a modal for the extension, but I found website shortcut key event has higher priority than input key press, so I cannot get the input letter. For example, if press letter L in TikTok, it will trigger like a video instead to add L to the input text field, any solution to avoid this and capture input press first?

The sample code works as @wOxxOm mentioned above

function untilDocumentReady() {
    function fn(e: KeyboardEvent) {
       var key = e.key;
       console.log("You pressed a key: " + key)
       e.stopPropagation()
    }

    window.addEventListener('keydown', fn, true)
}

or

function untilDocumentReady() {
   ...

    window.addEventListener('keydown', (event) => {
      var key = event.key;
      console.log("untilDocumentReady - You pressed a key: " + key)
      event.stopPropagation()
    }, true);
  })
}