To use Unreal Engine, you must first install Epic Games Launcher:

1. Access the website (https://www.unrealengine.com)
2. Register and download Epic Games Launcher
3. Install and start the launcher
4. Click the Unreal Engine tab on the left-hand side
5. Click on the Library tab that appears at the top of the screen
   
6. Click the + button next to ENGINE VERSIONS to add a version of Unreal Engine to the launcher

7. Click the Install button
8. Click the Launch button to start an already installed version:

It is possible to keep multiple versions of Unreal Engine. This book uses version 4.20.3, but the examples were tested in version 4.22.0 and worked well. Blueprint is already a stable technology. The examples created in this book should work without problems in later versions.