How to Hide Call Now Button Admin Menus

function plt_hide_call_now_button_menus() {
	//Hide "Call Now Button0".
	remove_menu_page('call-now-button');
	//Hide "Call Now Button0 → My button".
	remove_submenu_page('call-now-button', 'call-now-button');
	//Hide "Call Now Button0 → Unlock features".
	remove_submenu_page('call-now-button', 'call-now-button-upgrade');
	//Hide "Call Now Button0 → Settings".
	remove_submenu_page('call-now-button', 'call-now-button-settings');
}

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

Where do I put this code?