Keydown Event Listener and Focus

Hello readers! Welcome to my first blog where I will be discussing the issues and resolution I had with the "Keydown" event listener in JavaScript. When trying to implement my last event listener I struggled for an hour trying to understand why it was not working although the logic was all there. Here is the original HTML, JavaScript, and CSS for my code:
HTML

<img src="https://pbs.twimg.com/profile_images/1364220282790109188/uT0fQV56_400x400.jpg" alt="blue party hat" id="easterEgg" tabindex="0">
    <div>

JavaScript

const easterEggImage = document.getElementById('easterEgg') 

easterEggImage.addEventListener("keydown", handleKeyDown);

function handleKeyDown(event) {
  if (event.key.toLowerCase() === "h") {
    easterEggImage.style.display = "block";
  }
}

CSS

#easterEgg {
    display: none;
    position: fixed;
    left: 0;
    bottom: 0px;
    margin-left: 5%;
    max-width: 90%;
}

The idea of this was to make an image appear whenever the user pressed the "h" key. Unfortunately it was not working and I could not understand why. After doing research I became more familiar with the concepts of "Event Delegation" and "direct event attachment". When I was using the descendant element easterEggImage I was only giving instruction for to apply the event to that element only. This is not what I intended so in order to fix this I attached the addEventListener to the document instead. Here is the working code below:

document.addEventListener("keydown", handleKeyDown);

Now my keydown event will trigger anywhere in the document! So after my hour long struggle I was able to get my image to appear with this function.