Append param (utm, gclid etc) in internal URL

url-param.js

<script>
document.addEventListener('DOMContentLoaded', function () {
	const queryString = window.location.search;

	if (!queryString) return; // no UTM parameters, nothing to do

	const links = document.querySelectorAll('a[href^="/"], a[href*="' + location.hostname + '"]');

	links.forEach(link => {
		const url = new URL(link.href);
		if (!url.search) {
			url.search = queryString;
			link.href = url.toString();
		}
	});
});
</script>