Yes, the Paymentus payment site requires third-party cookies be enabled for their site. When cookies are disabled you are unable to make payments or access bill information online, and you will see a message that you must have third-party cookies enabled in your web browser.
What are cookies?
Cookies are small files which are stored on a user's computer. They are designed to hold a modest amount of data specific to a particular client and website, and can be accessed either by the web server or the client computer. This allows the server to deliver a page tailored to a particular user, or the page itself can contain some script which is aware of the data in the cookie and so is able to carry information from one visit to the website (or related site) to the next.