Copy and paste the following into your admin custom header or footer box. If someone visits using any IE version, they are redirected to Microsoft's official page telling the user that IE is almost completely non-supported. So use a real browser already! 😉 Or, replace the redirect URL to a custom page.
<script>if (/*@cc_on!@*/false || (!!window.MSInputMethodContext && !!document.documentMode)){window.location.href="https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support";}</script>
What the heck is this checking??
The @cc_on!@ part:
https://stackoverflow.com/questions/10072816/how-does-this-ie-check-work
The other part is for IE11 because the first part doesn't work with IE11.
If you change the redirect URL to https://zerosonesfun.github.io/IENOMORE/ this is what the user will be redirected to: