JSFiddle - React, Tailwind, and code Playground

HTML

<textarea id="textbox">-</textarea>

JavaScript

$('#textbox').keypress(function(event){
 
	var keycode = (event.keyCode ? event.keyCode : event.which);
	if(keycode == '13'){
		alert('You pressed a "enter" key in textbox');	
        document.getElementById('textbox').value = document.getElementById('textbox').value + "\n-";
        return false;
	}
	event.stopPropagation();
});