A simple hook to add your own buttons to the WordPress admin bar.
Add the following into your functions.php file and you’re ready to go!
/* Add Admin Bar Button */
add_action('admin_bar_menu', 'add_admin_bar_button', 100);
function add_admin_bar_button($admin_bar){
$admin_bar->add_menu( array(
'id' => 'my-button-id',
'title' => 'My Button',
'href' => 'https://www.mylink.com/',
'meta' => array(
'title' => __('My Button'),
'target' => '_blank',
),
));
}