function dateTimeFormat(timestamp, locale, str, ...opts) {
	const d = new Date(timestamp);
	return str.replace(/{(\d+)}/g, function(match, number) { 
		return typeof opts[number] != 'undefined'
			? new Intl.DateTimeFormat(locale, opts[number]).format(d)
			: match;
	});
}

console.log(dateTimeFormat("2021-11-19T19:19:36.598071-06:00", "en", "{0} at {1}!", {dateStyle:"short"}, {timeStyle:"long"}))
// => "11/19/21 at 7:19:36 PM CST!"