1document.addEventListener("keypress", function(event) {
2	// do stuff
3});

1document.addEventListener("keypress", function onEvent(event) {
2    if (event.key === "ArrowLeft") {
3        // Move Left
4    }
5    else if (event.key === "Enter") {
6        // Open Menu...
7    }
8});
9

1<input type="text" onkeypress="myFunction()">

1The keypress event has been deprecated, 
2you should look to use beforeinput : https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/beforeinput_event
3or keydown : https://developer.mozilla.org/en-US/docs/Web/API/Document/keydown_event
4instead.
5
6(And don't forget to like answers that help you !)

1// Create your variable and asssign it to your ID or Class in the document using document.querySelector.
2let name = document.querySelector('#exampleInputEmail1');
3
4// Now use your variable and add an event listener to it plus your keypress, event and styling
5name.addEventListener("keypress", (event) => {
6   name.style.border = "3px solid #28a745";
7});