Java Question Problem creating a library

Hi I am creating a B4A library from an Android Studio project using the Simple Library Compiler following the tutorial
The project consists in a single java class (called MyClass.java) that use methods from an external .jar lib (called ExternalLib.jar).
As the tutorial says to create the library (that I will call MyLib.jar) I put MyClass.java in the src folder and ExternalLib.jar in the libs folder.
After compiling the lib and referencing it in my new project I can call the methods of MyClass.java but the ones that use methods of ExternalLib.jar produce java.lang.ClassNotFoundException.
Trying to investigate I opened MyLib.jar with WinRAR and I only found MyClass.class so I have no idea where ExternalLib.jar went

Put ExternalLib.jar in your additional libraries folder together withMyLib.jar and MyLib.xml. Add

#AdditionalJar: ExternalLib

to the Project Attributes region in your Main module.

Now it works, thank you