How to Hide QuickPop Admin Menus

function plt_hide_quickpop_popup_builder_menus() {
	//Hide "My Brindle".
	remove_menu_page('my-brindle.php');
	//Hide "My Brindle → My Brindle".
	remove_submenu_page('my-brindle.php', 'my-brindle.php');
	//Hide "My Brindle → QuickPop".
	remove_submenu_page('my-brindle.php', 'post-new.php?post_type=qp_popup');
	//Hide "My Brindle → Submissions".
	remove_submenu_page('my-brindle.php', 'edit.php?post_type=qp_submissions');
}

add_action('admin_menu', 'plt_hide_quickpop_popup_builder_menus', 21);

Where do I put this code?