JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#seccion">prueba</a>
<input type="text" id="inputBox" />

JavaScript

$(document).ready(function() {
$('a[href*=#]').click(function(){
    var sHash = $(this).attr('href').replace("#","");
    sHash = "box" + sHash.charAt(0).toUpperCase() + sHash.slice(1);
    $("#inputBox").val(sHash);
    
    
});
});