Extract wa.me from autodetected cellphone starting with 3xx. Also working with 3xx-yyyyyyy or 3xx yyyyyyy

phoneToWA.user.js

// ==UserScript==
// @name     Phone Number Id
// @author		emmunaf ([email protected])
// @version  1
// @grant    none
// ==/UserScript==


(function () {
 	const trackRegexUS = /((\d{3})\s?\-?\s?(\d{4}))|(\(\d{3}\)\s?\d{3}\s?\-\s?\d{4})|(\d{3}\s\d{4})/g;
 	const trackRegex = /(3(\d{2})\s?\-?\s?(\d{7}))/g;

    // tags we will scan looking for un-hyperlinked urls
    var allowedParents = [
        "abbr", "acronym", "address", "applet", "b", "bdo", "big", "blockquote", "body", 
        "caption", "center", "cite", "code", "dd", "del", "div", "dfn", "dt", "em", 
        "fieldset", "font", "form", "h1", "h2", "h3", "h4", "h5", "h6", "i", "iframe",
        "ins", "kdb", "li", "nobr", "object", "pre", "p", "q", "samp", "small", "span", "strike", 
        "s", "strong", "sub", "sup", "td", "th", "tt", "u", "var"
        ];
    
    var xpath = "//text()[(parent::" + allowedParents.join(" or parent::") + ")" + "]";

    var candidates = document.evaluate(xpath, document, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);

    for (var cand = null, i = 0; (cand = candidates.snapshotItem(i)); i++) {
        if (trackRegex.test(cand.nodeValue)) {
            var span = document.createElement("span");
            var source = cand.nodeValue;
            
            cand.parentNode.replaceChild(span, cand);

            trackRegex.lastIndex = 0;
            for (var match = null, lastLastIndex = 0; (match = trackRegex.exec(source)); ) {
                span.appendChild(document.createTextNode(source.substring(lastLastIndex, match.index)));
                
                var a = document.createElement("i");
                var b = document.createElement("b");
              	 var c = document.createElement('a');
                var cleanPhone = match[0].replace(/ /g,"");
                var linkText = document.createTextNode(cleanPhone);
                c.appendChild(linkText);
                c.title = cleanPhone;
                c.target = "_blank";
                c.href = "https://wa.me/39"+cleanPhone+"?text=Buongiorno";
              
                b.appendChild(document.createTextNode(match[0]));
                a.appendChild(b);
                span.appendChild(a);
              	
              	span.appendChild(c);

                lastLastIndex = trackRegex.lastIndex;
            }

            span.appendChild(document.createTextNode(source.substring(lastLastIndex)));
            span.normalize();
        }
    }

})();
/*
var a = document.createElement('a');
      var linkText = document.createTextNode("my title text");
      a.appendChild(linkText);
      a.title = "my title text";
      a.href = "http://example.com";
      document.body.appendChild(a);
      */