Okay, that up ^-- was fixed with a crappy old apache2 ".conf" file. That's on me.
And now … after all of that hard work, multiple experts (yeah, that's right - YOU two, @aftechro and @johnny), on the final step that normally gave me the HTTP ERROR 500, I got … this:
YAY!!!
So, now I (and you guys) know a few things…
- It will work on Debian 11
- It works with the (L)AMP stack as follows: Apache 2.4.59, MySQL 15.1\MariaDB 10.5.23, PHP 7.4.33
- It's probably a very good idea to include the whois into the install script; I don't know if it helped, but everything is working now, so…
Everyone's observation of events was instrumental. I'm very happy with things so far (it is, after all, the beginning). Thank you, muchly. Very muchly.