Remove Facebook button from WP Login?

I was wondering whether there is a good way to remove the Facebook Login button from wp-admin/wp-login.php as the admin users don’t use social login and the normal site users should not use the wp-admin part at all but log in on the frontend directly using the facebook login button from your plugin.

I have tried the following:

add_action( 'init', function() {
    // facebook social plugin remove on wp admin login page
    remove_action('login_form', array('Facebook_Login', 'add_button_to_login_form'), 10);
});

However that did not work out. Also as the Plugin itself is not available as a global variable the official reference here does not provide any leads: https://codex.www.ads-software.com/Function_Reference/remove_action

Many thanks!

https://www.ads-software.com/plugins/wp-facebook-login/