How to lock pc when lid is closed Ubuntu 22.04 LTS?

Question

I've installed Ubuntu 22.04.3 LTS and configured all my environments, but when I was about to close my laptop lid, I encountered an issue. Instead of suspending, the external monitor continues to operate.

First, I attempted to install gnome-tweaks, but unfortunately, it doesn't seem to resolve the problem: the relative option was already enabled, yet the issue persists. Next, I tried modifying the /etc/systemd/logind.conf file. Specifically, I commented out the following lines:

HandleLidSwitch=suspend
HandleLidSwitchExternalPower=suspend
HandleLidSwitchDocked=suspend

After running systemctl restart systemd-logind.service, I still couldn't suspend my external monitor.

What other steps can I take to address this issue?
Thanks in advance.

Answer 1

I found out the answer to this question and I followed All Ubuntus and Ubuntu 22.04 (Upower based) sections to solve my problem.