Ubuntu 18 Disable Auto Login

I enabled Autologin during current installation of Ubuntu 18 Bionic Beaver.

I would like to Disable the AutoLogin but going to:

"Settings -> Details -> Users"

Doesn't give me the ability to turn the autologin off.

My last resort is to redo the installation without enabling it.

Solution 1:

I figured it out!

At

"Settings -> Details -> Users"

on the top right corner there was a button to "Unlock".

Clicking that, entering my password gave me the permission to use that slider to turn Autlogin off.

Solution 2:

There are some bugs in configuring with GUI on Ubuntu 18.10. But the configuration can be changed by editing /etc/gdm/custom.conf, comment out lines related to auto login:

[daemon]
#AutomaticLoginEnable=True
#AutomaticLogin=username