Adding icon to button in admin orders page

Use a dashicon in your custom CSS perhaps? https://developer.www.ads-software.com/resource/dashicons/

Even with my own stylesheet added, it does not seem to add the icon to the button. Instead i get the button text, with a square box with the unicode or hex code of the icon – so the stylesheet is actually adding the content – just not rendering it as an icon?

Here is my plugin code to add a new button to the orders page:

function foo_add_my_action($actions, $the_order){
        /**
         * Merge arrays so that our button is first
         */
        $newActions = [];
        if($the_order->is_paid()){
            $newActions['myLink'] = array(
                'url' => plugin_dir_url( __FILE__ ) . 'somepage.php?bookId=' . $the_order->id,
                'name' => 'my link',
                'action' => 'my-link'
            );
        }

        return array_merge($newActions, $actions);
    }
    add_filter( 'woocommerce_admin_order_actions', 'foo_add_my_action', 10, 2);

And the css rule:

.my-link:AFTER{
    content: "\f227";
}

…results in a button (that works btw) with the text my-link and a square with F227 in it.

Ignore previous post, the glyph is now showing in the button fine.

The problem i am now having is displaying JUST the icon. At the moment it displays the icon and the link text. The other buttons don’t do this, despite having the link text defined too (and if i leave the text blank in the above array, i lose the data-tip, which i want).

There is CSS in WC which hides text when there is an icon.