How to Hide myStickymenu Admin Menus

function plt_hide_mystickymenu_menus() {
	//Hide "myStickymenu".
	remove_menu_page('my-stickymenu-settings');
	//Hide "myStickymenu → Settings".
	remove_submenu_page('my-stickymenu-settings', 'my-stickymenu-settings');
	//Hide "myStickymenu → Welcome Bar".
	remove_submenu_page('my-stickymenu-settings', 'my-stickymenu-welcomebar');
	//Hide "myStickymenu → Upgrade to Pro".
	remove_submenu_page('my-stickymenu-settings', 'my-stickymenu-upgrade');
}

add_action('admin_menu', 'plt_hide_mystickymenu_menus', 11);

Where do I put this code?