Add menu item to WordPress admin bar

function custom_node_example($wp_admin_bar){
    $args = array(
        'id' => 'custom-node',
        'title' => 'Custom Node',
        'href' => 'http://example.com/page/',
        'meta' => array(
            'class' => 'custom-node-class'
        )
    );
    $wp_admin_bar->add_node($args);
}

add_action('admin_bar_menu', 'custom_node_example', 50);

Custom Menu Item Position In WordPress Admin Bar (Toolbar) | Natko Hasić

Adding a node to a custom position in WordPress Toolbar is easier than it looks. This article shows how to place menu item anywhere you want.

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