How do i Make a "keyLogger" that types when i type in a input in JavaScript

Ive tried this, but it doesnt work, i've also tried to search for more info but i havent found anything.

document.getElementById("Text").addEventListener("select", myFunction);
function myFunction(){
document.body.addEventListener('keyup', function(event) {
    document.getElementById("Solution").innerHTML+=(event.key);
});
}

I want to know if there is a way to achieve something like this:

Pseudo-Code:

if(inputText==selected){
keyloggerFunction code... }

the keylogger works more or less, but i dont know if the if statement would be posible in any way.