Launcher can not install Fortnite after UE4 is installed

I recently installed UE4 version 4.24.3 using the “Epic Games Launcher”.
Now my son wanted me to install Fortnite for him but this mission seems to be impossible:
When I go to “https://www.epicgames.com/fortnite/en-US/download” it downloads a file for the launcher install:
“EpicInstaller-10.15.1-fortnite-305711e56666436ca4782404bb9020ed.msi”
When I install it, nothing happens: The game launcher still shows as if I am only using Unreal Engine, and there is no way for me to reach the fortnite installation from the launcher. It is just not there.
How can I install both UE4 and Fortnite using the game launcher?
Is there another way to download the Fortnite installation files?

To get to the games library, you should ensure that the launcher’s settings are not hiding it.

  1. Click the settings cog in the bottom left of the Epic Games Launcher.
  2. Ensure that the “Hide Game Library” option is not ticked.
  3. On the left panel, under the Epic Games logo, you should now see three extra links “Home”, “Store”, and “Library”.
  4. You can find Fortnite in the Store.