Add Estimations in Checkout form.js

function cleanEstimates() {
    // remove all prices and errors
    $('#shipping_options li').each(function() {
        $(this).children().last().detach();
    });
    // add empty messages - placeholders
    $('#shipping_options li').each(function() {
        $(this).append('<span></span>')
    });
}

function shippingEstimates() {
    cleanEstimates();
    if ($('#order_shipping_address_country').val() != "" && $('#order_shipping_address_region').val() != "") {
        $.ajax({
            method: "POST",
            url: "/checkout/shipping_estimate",
            data: {
                estimate: {
                    country: $('#order_shipping_address_country').val(),
                    region: $('#order_shipping_address_region').val(),
                    municipality: $('#order_shipping_address_municipality').val(),
                    postal: $('#order_shipping_address_postal').val(),
                    city: $('#order_shipping_address_city').val(),
                    address: $('#order_shipping_address_address').val(),
                }
            }
        }).done(function(data) {
            for (var i = 0; i < data.length; i++) {
                let amount;
                let old_currency;
                let new_currency;
                let currency_amount;
                if (typeof(accounting) != "undefined") {
                    old_currency = sessionStorage.getItem('store_currency');
                    new_currency = $.trim(sessionStorage.getItem('global_currency'));
                    if (old_currency == new_currency) {
                        currency_amount = data[i].table.price;
                    } else {
                        amount = accounting.unformat(data[i].table.price, i18n_decimal_mark);
                        currency_amount = accounting.formatMoney(fx.convert(amount, {
                            from: old_currency,
                            to: new_currency
                        }), {
                            symbol: {
                                EUR: "€",
                                GBP: "₤"
                            } [new_currency]
                        })
                    }
                }
                let shipping_method = $('#shipping_options #order_shipping_method_' + data[i].table.id);
                // remove any previous messages & placeholders
                shipping_method.parent().children().last().detach();
                if (data[i].table.error) {
                    // disable options with errors
                    shipping_method.attr('disabled', 'disabled');
                    shipping_method.prop('checked', false);
                    // add error messages
                    shipping_method.parent().append("<p class='shipping_information'><i>" + data[i].table.error_message + "</i></p>")
                } else {
                    // enable options
                    shipping_method.attr('disabled', false);
                    if ($("#shipping_options").find("input[type='radio']:checked").not("[disabled]").length == 0) {
                        shipping_method.prop('checked', true);
                    }
                    // add formatted shipping prices
                    shipping_method.parent().append("<p class='shipping_information'><i>" + (typeof(accounting) != "undefined" ? currency_amount : data[i].table.price) + "</i></p>")
                }
            }
            // Disable Review Order Button if Invalid Shipping Method
            function CheckShippingMethods() {
                if ($("#shipping_options").find("input[type='radio']:checked").not("[disabled]").length > 0) {
                    $("#submit_review_order_2").prop("disabled", false);
                } else {
                    $("#submit_review_order_2").prop("disabled", true);
                }
            }
            $(document).ready(CheckShippingMethods);
            $("#shipping_options input[type='radio']").on('change', CheckShippingMethods);
        });
    } else {
        // no Country or Region filled, clear shipping estimate info
        cleanEstimates();
    }
}
/* LISTENERS */
var debounceTimer = null; // so it does only a single request instead of lots of them.
$('#order_shipping_address_country, #order_shipping_address_region, #order_shipping_address_municipality, #order_shipping_address_city, #order_shipping_address_postal, #order_shipping_address_address').change(function() {
    clearTimeout(debounceTimer);
    debounceTimer = setTimeout(function() {
        shippingEstimates();
    }, 300);
});
// END OF LISTENERS
$(document).ready(function() {
    // add empty messages - placeholders
    $('#shipping_options li').each(function() {
        $(this).append('<span></span>')
    });
    shippingEstimates();
})