This articicle explains how to add phone icon link on your mobile like this:

Add following code to the /wp-content/themes/myhome/footer.php just before </body>

<style>
    .top-phone {
        display: none;
        position: absolute;
        z-index: 999999;
        top: 18px;
        right: 54px
    }

    .top-phone i {
        color: orange;
        font-size: 24px;
    }

    @media (max-width: 1023px) {
        .top-phone {
            display: inline-block;
        }
    }
</style>
<script>
    jQuery(window).on("load", function () {
        $(".menu_inner").append('<a href="tel:123" class="top-phone"><i aria-hidden="true" class="fa fa-phone"></i>');
    });
</script>