How to get smartselect value


<a class="link smart-select smart-select--custom smart-select-init">
                <select name="price-low-high-1" id="local_sort_price">
                    <option value="low" selected>sort by decrease</option>
                    <option value="high">sort by increase</option>
                <div class="item-content">
                                <div class="item-inner">
                                    <div class="item-title">Price:</div>
                            <td class="right">
                                <img class="dropdown-ic" src="~/Resources/img/ic_dropdown.svg" alt="">

routes init:

 smartSelect: {
        el: ".smart-select--custom",
        openIn: "sheet",
        sheetCloseLinkText: "Close",
        renderItem: function (item, index) {
            return '<li><label class="item-radio item-check-location item-content ' + item.value + '">' +
                '<input type="radio" name="' + item.inputName + '" value="' + item.value + '" ' + (item.selected ? 'checked' : '') + '>' +
                '<div class="item-inner item-inner-custom">' +
                '<div class="item-title">' + item.text + '</div>' +
                '</div>' +
                '<div class="item-radio__checked">' +
                '<span></span>' +
                '</div>' +
        closeOnSelect: true,

I cann’t get value after select, I tried to use

var smartSelect = app.smartSelect.get('.smart-select--custom').selectEl;

but it still not work. . . So how can I get value in that select option to sort information by decrease or increase price?
This is the client:

Thấp đến cao is Increase and Cao đến thấp is Decrease.