Some websites may incorrectly identify your iOS/iPadOS Safari User Agent when used in one or other of its browsing modes - of which there are two - these being Desktop and Mobile. Misidentification of the browser Agent can often manifest as the website reporting that your browser is out of date, or won’t properly render a page.
It’s easy to switch between modes if a website isn’t functioning correctly. From the desired web-page, touch the aA icon at the left of the Address Bar; this will reveal a menu. From the menu select Website Settings, then select (or deselect) Request Desktop Website, then tap Done. Now refresh the webpage.