How to use sendBeacon for tracking checkout status before page redirect in JavaScript?

I have a function submitOrderRequestForm that submits form data via an AJAX call and redirects the user to another page upon a successful response. I want to track the status “REQUEST_FLOW” using the sendBeacon API before the page redirects.

Here is my current code:

function submitOrderRequestForm() {
            $('#mobile_number').val($("#phone-number").intlTelInput("getNumber"));
            $('#contact_number').val($("#phone-number").intlTelInput("getNumber"));
            $('#orderType').val('order_request');
            // $('#consentEmailValue').val($("#consentEmail").is(":checked") ? 1 : 0);
            // $('#consentSMSValue').val($("#consentSMS").is(":checked") ? 1 : 0);
            $('#consentBothValue').val($("#consentBoth").is(":checked") ? 1 : 0);

            getToken();
            // $("#continueBtn").prop("disabled",true);
            $.ajax({
                url: "{{URL::route('item.borrow-post',$shoppingCart->id)}}",
                type: "post",
                async: false,
                data: $("#reservationForm").serialize(),
                success: function (data) {
                    if (data.type=='success') {
                        window.location.href = "{{URL::route('submit-order-request')}}";
                        checkout_tracking_status = "REQUEST_FLOW";
                    }
                },
}

I want to use the sendBeacon API to send tracking data to the server for the checkout_tracking_status = “REQUEST_FLOW” event. However, I’m not sure how to implement this correctly to ensure the beacon sends the data reliably before the page redirects.

Where should I place the sendBeacon call to ensure it executes before the redirect?
How can I structure the data payload for sendBeacon?

Any guidance or examples would be greatly appreciated.