I take over the website in the company
The original company that made the website use Joomla! version 3.9
I want to add a new page at the front office
but the back office doesn't have the option in the Control Panel to let me select modules or install anything
like this: It doesn't have System, Users, Extensions ... etc.
How can I fix this?
It sounds like your account has too low privileges.
You should be a Super User, otherwise you will have restrictions in the administration panel.
Only a Super User can create new Super Users.
You can also add a Joomla Super User from phpMyAdmin: https://www.itoctopus.com/how-to-add-a-joomla-super-user-from-phpmyadmin
Best of luck.
