Implementing native android .aar file or .aidl in Nativescript throws native calss object without access to methods

Environment
Provide version numbers for the following components (information can be retrieved by running tns info in your project folder or by inspecting the package.json of the project):

• CLI:
• Cross-platform modules:
• Android Runtime:
• iOS Runtime:
• Plugin(s):
  Android
  Describe the bug

I have an Android SDk done with java whic I already converted to .aar file. I created a plugin and placed the aar file in App_Resources/Android/libs directory. In my index.js file, I have this

var intent = new android.content.Intent(application.android.foregroundActivity, com.iposprinter.printertestdemo.IPosPrinterTestDemo.class)
intent.setFlags(android.content.Intent.FLAG_ACTIVITY_NEW_TASK);
application.android.foregroundActivity.startActivity(intent);

This cause the sdk to display.

Doing this

var iposprinter=new com.iposprinter.printertestdemo.IPosPrinterTestDemo()
console.log(iposprinter) //outputs com.iposprinter.printertestdemo.IPosPrinterTestDemo@682890e
while this `console.log(iposprinter.printerInit) outputs undefined`

while this

`console.log(iposprinter.printerInit) outputs undefined`
console.log(iposprinter.printerInit()) outputs undefined
TypeError: iposprinter.printerInit is not a function

How do I call methods from this package?
To Reproduce

Expected behavior

Sample project

Additional context

Start with the plugin's index.js and the .aar placement under App_Resources/Android/libs, then reproduce the native object and printerInit logs from the issue. Check how the Android runtime exposes the packaged Java class; done means the SDK methods are available and can be called without the TypeError.