How to always expand main menu in IntelliJ IDE

Environment

Linux, Windows

Problem

Main menu is always hidden under hamburger, extra clicks are required to access it

Solution

Right-click the main toolbar for options:

Select "Merge with Main Toolbar" to show the Main menu in the same line with the main toolbar

Select "Show above Main Toolbar" to show the Main menu on the separate line

Additional information

In MacOS, the main menu position is always on the System Menu bar.