How to add Buy Now button on Product page – WordPress/woocommerce?

add_filter('woocommerce_add_to_cart_redirect', 'malpani_redirect_checkout_add_cart');

        function malpani_redirect_checkout_add_cart()
        {
            if (isset($_POST["buynow"]) && $_POST["buynow"] === "2") {
                return wc_get_checkout_url();
            }

        }

        add_filter('woocommerce_after_add_to_cart_button', 'malpani_add_buy_button');
        function malpani_add_buy_button()
        {
        echo '<input id="buynowinput" name="buynow" value="1" hidden>
            <button type="button" id="buy_now" class="buy_now button">Buy Now</button>
            <script>
                jQuery(document).ready(function ($) {
                    $("#buy_now").click(function (e) {
                        $("#buynowinput").val(2);
                        $(".single_add_to_cart_button").click();
                        e.stopPropagation();
                        e.preventDefault();
                    })
                });
            </script>';