Settings
In the Unity-Editor go to the menu bar at the top of the Engine and select:
Edit --> Preferences...
Once opened select the option “External Tools”.
From there, you should see some more information on the right side of this window, there should also be an option called “External Script Editor” (In my picture, you can see I already selected the Visual Studio Community 2022 version). To select something just perform a left mouse click on the arrow right and select an editor of your choice. If you can’t see the editor you want to use, just press the “Browse…” field and search on your computer for the .exe file of your editor. You can use editors like:
- Visual Studio
- Visual Code
- IntelliJ
- Notepad++
But you can also use some other editors not listed here.