I can tell you that this feature for sure works on Joomla 4.1.5 as we're using it extensively on our own site here. For example, if you visit https://www.akeeba.com/downloads you get redirected to https://www.akeeba.com/download.html (the actual URL of our download menu item). This is done with Admin Tools' URL Redirection feature.
It is very important to note that the prerequisite for this to work is that your site has both “Search Engine Friendly URLs” and “Use URL Rewriting” enabled in its Global Configuration. The latter option requires having an Apache, Litespeed, NginX or IIS web server with the appropriate server configuration file (.htaccess for the former two, web.config for the latter, typically nginx.conf for NginX but it depends on the server set up) with the Joomla URL rewriting code block in it. For example, if you have an Apache or LIteSpeed server (most sites!) you can either use Admin Tools' .htaccess Maker OR renamed Joomla's htaccess.txt file to .htaccess minding that dot in front of htaccess, it's important.
Without using these two options you can only perform redirections by adding index.php?/ in the URL, i.e. https://gregoriusblad.nl/index.php?/woord which does redirect you correctly as you can see.
So, what do the two Global Configuration options really do?
The “Search Engine Friendly URLs” allow you to drop the question mark. The previous URL could now be written as https://gregoriusblad.nl/index.php/woord and still work. Enabling this options does not require a .htaccess, web.config or nginx.conf file. This all happens inside Joomla's initialisation code which runs before Admin Tools' URL Rewriting feature.
The “Use URL Rewriting” allows you to remove the /index.php from the URL. The previous URL could now be written as https://gregoriusblad.nl/woord and still work. This feature does require a .htaccess, web.config or nginx.conf file. The magic happens inside your web server, before Joomla even starts executing. Basically, it internally rewrites the URL https://gregoriusblad.nl/woord to https://gregoriusblad.nl/index.php/woord and asks Joomla to handle that latter URL. That's why this option is only available if the “Search Engine Friendly URLs” option is enabled.
Since all of that happens outside of Admin Tools it's not under our control.
I hope that helps!
Nicholas K. Dionysopoulos
Lead Developer and Director
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