It looks like you’re using Microsoft Internet Explorer as your web browser. This is now considered ‘end-of-life’, and Microsoft is withdrawing support for it because it uses outdated technology. This means that it will no longer receive important security updates and previous bugs will not be fixed.
This means that the risk and cost are placed on service providers to develop twice for modern browsers and again for Internet Explorer. As free, modern alternatives are available for most platforms it is difficult to justify spending public money on further development.
Please see the Withdrawal of support for Internet Explorer notice from NHS Digital for more information and guidance.