How to Hide One Two Three Post Admin Menus

function plt_hide_one_two_three_post_menus() {
	//Hide "One Two Three Post".
	remove_menu_page('one-two-three-post');
	//Hide "One Two Three Post → New / Compose".
	remove_submenu_page('one-two-three-post', 'one-two-three-post');
	//Hide "One Two Three Post → Scheduled".
	remove_submenu_page('one-two-three-post', 'one-two-three-post-scheduled');
	//Hide "One Two Three Post → All Posts".
	remove_submenu_page('one-two-three-post', 'edit.php?post_type=ottpost_fb_post');
	//Hide "One Two Three Post → Settings".
	remove_submenu_page('one-two-three-post', 'one-two-three-post-settings');
}

add_action('admin_menu', 'plt_hide_one_two_three_post_menus', 11);
Where do I put this code?