Wordpress widget with acf snippet

widget.php

<?php

function registerThemeWidgets()
{
    register_widget('Example_widget');
}

add_action('widgets_init', 'registerThemeWidgets');

class Example_widget extends WP_Widget
{
    function __construct()
    {
        parent::__construct(
            'example_widget',
            'Example'
        );
    }

    public function widget($args, $instance)
    {
        echo $args['before_widget'];
        echo $args['after_widget'];
    }

    public function form($instance)
    {

    }

}

function exampleWidgetParams($params)
{
    $widgetName = $params[0]['widget_name'];
    $widgetId = $params[0]['widget_id'];

    if ($widgetName != 'Example') {
        return $params;
    }

    $content = get_field('content', 'widget_' . $widgetId);

    if ($content) {
        $params[0]['before_widget'] .= $content;
    }

    return $params;
}

add_filter('dynamic_sidebar_params', 'exampleWidgetParams');