how to get the variant if i enter from keyboard using javascript code example

Example 1: jquery on enter key pressed

//jQuery detect user pressing enter
$(document).on('keypress',function(e) {
    if(e.which == 13) {
        alert('User pressed Enter!');
    }
});

Example 2: js when key is pressed

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