function plt_hide_fcm_push_notification_from_wp_menus() {
//Hide the "Settings → FCM Push Notification from WP" menu.
remove_submenu_page('options-general.php', 'fcmdpplgpn_push_notification');
}
add_action('admin_menu', 'plt_hide_fcm_push_notification_from_wp_menus', 11);