How to Hide Double Opt-In (Contact Form 7, Avada) - GDPR Ready Admin Menus

function plt_hide_double_opt_in_menus() {
	//Hide "Forge12 Double Opt-In".
	remove_menu_page('f12-cf7-doubleoptin');
	//Hide "Forge12 Double Opt-In → Dashboard".
	remove_submenu_page('f12-cf7-doubleoptin', 'f12-cf7-doubleoptin');
	//Hide "Forge12 Double Opt-In → Settings".
	remove_submenu_page('f12-cf7-doubleoptin', 'f12-cf7-doubleoptin_settings');
	//Hide "Forge12 Double Opt-In → Categories".
	remove_submenu_page('f12-cf7-doubleoptin', 'f12-cf7-doubleoptin_categories');
	//Hide "Forge12 Double Opt-In → Database".
	remove_submenu_page('f12-cf7-doubleoptin', 'f12-cf7-doubleoptin_database');
}

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

Where do I put this code?