My Character doesn't move :(

Explain how your code is misbehaving…
When i pressing any Button(ArrowButtons) then
nothing happens.

// Paste your code here
document.addEventListener('keydown', sendKeyDown);
function sendKeyDown(event) {
  var code = event.code;
 if (code == 'ArrowLeft') avatar.position.x = avatar.position.x - 5;
 if (code == 'ArrowRight') avatar.position.x = avatar.position.x + 5;
 if (code == 'ArrowUp') avatar.position.x = avatar.position.z - 5;
 if (code == 'ArrowDown') avatar.position.z = avatar.position.z + 5;

Include any more information that you like here...
I am using The Google Chrome WebBrowser and i am confused.

You may need to copy and paste all of your code in here, not just this part of it. From what I can tell here, something should be happening, though there is a small typo. For the 'ArrowUp' line, it should be changing the avatar’s Z position, not the X position.

So, instead of this:

 if (code == 'ArrowUp') avatar.position.x = avatar.position.z - 5;

It should read:

 if (code == 'ArrowUp') avatar.position.z = avatar.position.z - 5;

If I use make that change, then your code works with the rest of mine.

But even before that change, the left, right, and down arrow keys worked for me. So if you’re still having problems after fixing that line, copy & paste all of your code here and I’ll be happy to have a look.