JSFiddle - React, Tailwind, and code Playground

JavaScript

var url="http://h3gsat.altervista.org/DettagliCompleto.php?id=4567";
function urlParam(name){
    var results = new RegExp('[\\?&]' + name + '=([^&#]*)').exec(url);
    return results[1] || 0;
}

// http://h3gsat.altervista.org/DettagliCompleto.php?id=4567
var value_of_id=urlParam('id');        // 6

console.log(value_of_id);