intl-tel-input getExtension returning “null”

Question

I have been trying to get the Extension of the mobile number entered. Every other variable is working fine. The extension variable is returning Null. It seems that it is passing a null value to the POST.

<input type="tel" id="mobile" placeholder="Mobile Number" maxlength="10" >

    <script>
        //Initialize the plugin
            $("#mobile").intlTelInput({
                initialCountry: "auto",
                nationalMode: "true",
                utilsScript:'https://cdnjs.cloudflare.com/ajax/libs/intl-tel-input/8.5.0/js/utils.js',
                geoIpLookup: function(callback) {
                $.get("https://ipinfo.io", function() {}, "jsonp").always(function(resp) {
                    var countryCode = (resp && resp.country) ? resp.country : "";
                    callback(countryCode);
                });
            }
            });    

        //Ajax Registration
            $("#register").click(function(){

            var email = $("#email").val();
            var password = $("#password").val();
            var confirmpassword = $("#confirmpassword").val();
            var fname = $("#fname").val();
            var lname = $("#lname").val();
            var mobile = $("#mobile").val();
            var role = $("#role").val();
            var extension = $("#mobile").intlTelInput("getExtension");

            var data = "email=" + email + "&password=" + password + "&fname=" + fname + "&lname=" + lname + "&mobile=" + mobile + "&role=" + role + "&confirmpassword=" + confirmpassword + "&extension=" + extension;  

            $.ajax({
                type:"POST",
                url:"includes/register.php?",
                data:data,
                success:function(data)
                {
                    $("#register_output").html(data);
                }
            });
    </script>

Answer 1

I believe the getExtension method is now deprecated. If you want the country code on its own, you can get it at iti.s.dialCode . Something like this:

<label>Phone</label><input class="textbox" type="tel" name="phone" id="phone" value=""><br>

<script>
    var input = document.querySelector('#phone');

    var iti = intlTelInput(input, {
        utilsScript: 'assets/tel-input/js/utils.js',
        initialCountry: 'au'
    });

    $('#send').on('click', function(param) {
        var fullPhone = "+" + iti.s.dialCode + iti.getNumber();
        console.log(fullPhone)
    });
</script>