issuing: sudo systemctl start apache2
See "systemctl status apache2.service" and "journalctl -xe" for details.
systemctl status apache2.service shows:
* apache2.service - The Apache HTTP Server
Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset: enabled)
Active: failed (Result: exit-code) since Tue 2021-12-28 12:22:29 PST; 1min 13s ago
Docs: https://httpd.apache.org/docs/2.4/
Process: 666734 ExecStart=/usr/sbin/apachectl start (code=exited, status=1/FAILURE)
Dec 28 12:22:29 fungi systemd[1]: Starting The Apache HTTP Server...
Dec 28 12:22:29 fungi apachectl[666742]: [Tue Dec 28 12:22:29.728221 2021] [alias:warn] [pid 666742:tid 140581958831168] AH00671: The Alias directive in /etc/apache2/apache2.conf at line 231 will probably never match because it overlaps an earlier Alias.
Dec 28 12:22:29 fungi apachectl[666734]: Action 'start' failed.
Dec 28 12:22:29 fungi apachectl[666734]: The Apache error log may have more information.
Dec 28 12:22:29 fungi systemd[1]: apache2.service: Control process exited, code=exited, status=1/FAILURE
Dec 28 12:22:29 fungi systemd[1]: apache2.service: Failed with result 'exit-code'.
Dec 28 12:22:29 fungi systemd[1]: Failed to start The Apache HTTP Server.