Kartra conditional redirect w/ 3rd-party cookies blocked

/*
 * Force a group of two (or more) Kartra pages to select through conditional tracking links
 * (a work-around for on-page conditional redirects with custom domains and 3rd-party cookie blocking)
 * Replace the link URL with your (first) split conditional tracking link and place in HEADER tracking.
 * Author: Brian Katzung
 */
if (window.sessionStorage) {
var link = "https://account.krtra.com/t/something", key = 'did_' + link.replace(/.*\//, ''), now = +new Date, red = document.querySelector('meta[data-redirect]');
if (red) red.remove();
if (now - (sessionStorage[key] || 0) > 5000) { sessionStorage[key] = now; location = link; }
else delete sessionStorage[key];
}