Error when working with COM Port Java JSSC?

Question

Java

Good day! I'm trying to add the JSSC library to the project to read data from the com port, but I see an error:

Exception in thread "LWJGL Application" com.badlogic.gdx.utils.GdxRuntimeException: java.lang.NoClassDefFoundError: jssc/SerialPortList
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:133)
Caused by: java.lang.NoClassDefFoundError: jssc/SerialPortList
    at com.traction.game.SerialController.<init>(SerialController.java:7)
    at com.traction.game.Menu.create(Menu.java:13)
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:149)
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:126)
Caused by: java.lang.ClassNotFoundException: jssc.SerialPortList
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    ... 4 more

SerialController class:

import jssc.SerialPortList;
 
public class SerialController {
    public SerialController() {
        String[] portNames = SerialPortList.getPortNames();
        System.out.println("Ports");
        for(int i = 0; i < portNames.length; i++){
            System.out.println(portNames[i]);
        }
    }
}

calling from:

import com.badlogic.gdx.Game;
import com.badlogic.gdx.Screen;
 
public class Menu extends Game{
    @Override 
    public void create() {
        setScreen((Screen) new Traction());
        
 
        SerialController portController;
        portController = new SerialController();
    }
}

class Game - class of the libGDX library
If the constructor of the SerialController class is replaced by main, then everything is fine. What is the problem, please explain?