Subcriber to Author

add_action('jnews_after_account_nav',function (){
    $user = wp_get_current_user(get_current_user_id());
    if (user_can( $user, "subscriber" )){
        ?>
        <div class="frontend-submit-button" id="change-to-author">
            <a class="button" href="#"><i class="fa fa-file-text-o"></i>Switch to Author</a>
        </div>
        <script>
            (function ($){
                element = document.getElementById('change-to-author')
                element.addEventListener('click',function (e){
                    e.preventDefault()
                    $.ajax({
                        url:jnews_ajax_url,
                        method:'post',
                        dataType: 'json',
                        data: {
                            action:'subscribe_to_author',
                            user:<?=$user->ID?>,
                        },
                    }).success(function (data){
                        window.location.reload()
                    })
                })
            })(jQuery)
        </script>
        <?php
    }
});

add_action('jnews_ajax_subscribe_to_author',function (){
    $user = wp_get_current_user($_REQUEST['user']);
    $user->remove_role('subscriber');
    $user->add_role('author');
    wp_send_json();
});