buyItem not working

[Upd4ting]

Hi everyone,

When i'm calling the buyItem method on Android i'm having this issue.

System.err: java.lang.RuntimeException: Unable to start activity ComponentInfo{eu.test.mobileapp/com.android.billingclient.api.ProxyBillingActivity}: com.tns.NativeScriptException: Calling 
js method onActivityCreated failed
System.err: TypeError: args.activity.registerForActivityResult is not a function
System.err:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3781)
System.err:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3943)
System.err:     at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:103)
System.err:     at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
System.err:     at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
System.err:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2348)
System.err:     at android.os.Handler.dispatchMessage(Handler.java:106)
System.err:     at android.os.Looper.loopOnce(Looper.java:233)
System.err:     at android.os.Looper.loop(Looper.java:344)
System.err:     at android.app.ActivityThread.main(ActivityThread.java:8191)
System.err:     at java.lang.reflect.Method.invoke(Native Method)
System.err:     at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:584)
System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1034)
System.err: Caused by: com.tns.NativeScriptException: Calling js method onActivityCreated failed
System.err: TypeError: args.activity.registerForActivityResult is not a function
System.err:     at com.tns.Runtime.callJSMethodNative(Native Method)
System.err:     at com.tns.Runtime.dispatchCallJSMethodNative(Runtime.java:1302)
System.err:     at com.tns.Runtime.callJSMethodImpl(Runtime.java:1188)
System.err:     at com.tns.Runtime.callJSMethod(Runtime.java:1175)
System.err:     at com.tns.Runtime.callJSMethod(Runtime.java:1153)
System.err:     at com.tns.Runtime.callJSMethod(Runtime.java:1149)
System.err:     at com.tns.gen.android.app.Application_ActivityLifecycleCallbacks.onActivityCreated(Application_ActivityLifecycleCallbacks.java:20)
System.err:     at android.app.Application.dispatchActivityCreated(Application.java:367)
System.err:     at android.app.Activity.dispatchActivityCreated(Activity.java:1337)
System.err:     at android.app.Activity.onCreate(Activity.java:1623)
System.err:     at com.android.billingclient.api.ProxyBillingActivity.onCreate(com.android.billingclient:billing@@4.0.0:1)
System.err:     at android.app.Activity.performCreate(Activity.java:8129)
System.err:     at android.app.Activity.performCreate(Activity.java:8109)
System.err:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1344)
System.err:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3750)
System.err:     ... 12 more

Any idea?