如何在codeigniter HMVC中进行ajax调用

class My_controller extends MX_Controller {
    public function ajax_method() {
        // 检查是否为Ajax请求
        if ($this->input->is_ajax_request()) {
            // 处理请求逻辑
            $data = array('status' => 'success', 'message' => 'Ajax请求成功！');
            echo json_encode($data);
        } else {
            show_error('非法访问');
        }
    }
}

$route['my_module/ajax_method'] = 'my_module/my_controller/ajax_method';

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
    $("#myButton").click(function(){
        $.ajax({
            url: "<?php echo site_url('my_module/ajax_method'); ?>",
            type: "POST",
            data: { key: "value" },
            dataType: "json",
            success: function(response) {
                alert(response.message);
            },
            error: function(xhr, status, error) {
                console.log("Error: " + error);
            }
        });
    });
});
</script>

<button id="myButton">发起Ajax请求</button>