Voluum and CheckoutChamp events tracking integration code. It's based on JavaScript and sends events from a user's browsers. Each piece of code needs to be used on different pages in your CheckoutChamp funnel.

voluum-checkoutchamp-tracking.html

<!-- sale page/user entry point - Voluum postbacks -->
<script>
	document.addEventListener('DOMContentLoaded', async function(event) {
		try {
			const url = new URL(window.document.location.href),
			utmMedium = url.searchParams.get('utm_medium'),
			xoClickId = url.searchParams.get('utm_term');
			if (utmMedium === 'xo' && xoClickId) {
				// init user data
				localStorage.setItem('utmMedium', utmMedium);
				localStorage.setItem('xoClickId', xoClickId);
			}
		} catch(e) {
			console.log(e);
		}
	});
</script>
<!-- sale page/user entry point - Voluum postbacks -->

<!-- checkout page - Voluum postbacks -->
<script>
	document.addEventListener('DOMContentLoaded', async function(event) {
		function getPostbackURL() {
			try {
				const utmMedium = localStorage.getItem('utmMedium');
				const xoClickId = localStorage.getItem('xoClickId');
				if (utmMedium === 'xo' && xoClickId) {
					return 'https://your-voluum.domain/postback?cid='+xoClickId;
				}
			} catch(e) {
				console.log(e);
			}
		}
		if (getPostbackURL()) {
			navigator.sendBeacon(getPostbackURL()+'&et=begin_checkout');
		}
	});
</script>
<!-- checkout page - Voluum postbacks -->

<!-- thank-you/first upsell page - Voluum postbacks -->
<script>
	document.addEventListener('DOMContentLoaded', async function() {
		function getPostbackURL() {
			try {
				const utmMedium = localStorage.getItem('utmMedium');
				const xoClickId = localStorage.getItem('xoClickId');
				if (utmMedium === 'xo' && xoClickId) {
					return 'https://your-voluum.domain/postback?cid='+xoClickId;
				}
			} catch(e) {
				console.log(e);
			}
		}
		if (getPostbackURL()) {

			// const timeStamp = Math.round(Date.now() / 10000);
			// let url = getPostbackURL()+'&et=purchase&txid='+timeStamp;
			let url = getPostbackURL()+'&et=purchase';

			try {
				const orderDataRaw = sessionStorage.getItem("orderData");
				if (orderDataRaw) {
					const orderData = JSON.parse(orderDataRaw);
					const price = orderData.totalAmount;
					url += '&payout='+price;
					const orderId = orderData.orderId;
					url += '&txid='+orderId;
				}

			} catch(e) {
				console.log('Error: orderData');
				console.log(e);
			}

			navigator.sendBeacon(url);
		}
	});
</script>
<!-- thank-you/first upsell page - Voluum postbacks -->

Read full article about Voluum+CheckoutChamp postbacks integration before using this code.