Issue I am Unable used Generate Token api

[javagovindsharma]

Exception in thread "main" java.lang.RuntimeException: Authentication undefined: defaultAuth
at com.microsoft.powerbi.ApiClient.updateParamsForAuth(ApiClient.java:1019)
at com.microsoft.powerbi.ApiClient.buildRequest(ApiClient.java:895)
at com.microsoft.powerbi.ApiClient.buildCall(ApiClient.java:874)
at com.microsoft.powerbi.api.DashboardsApi.addDashboardCall(DashboardsApi.java:96)
at com.microsoft.powerbi.api.DashboardsApi.addDashboardValidateBeforeCall(DashboardsApi.java:108)
at com.microsoft.powerbi.api.DashboardsApi.addDashboardWithHttpInfo(DashboardsApi.java:133)
at com.microsoft.powerbi.api.DashboardsApi.addDashboard(DashboardsApi.java:121)
at powerBITest.powerbi_client.App.main(App.java:14)

[javagovindsharma]

import com.microsoft.powerbi.ApiException;
import com.microsoft.powerbi.api.DashboardsApi;
import com.microsoft.powerbi.models.AddDashboardRequest;
import com.microsoft.powerbi.models.Dashboard;

public class App {
public static void main(String[] args) {
DashboardsApi apiInstance = new DashboardsApi();
AddDashboardRequest requestParameters = new AddDashboardRequest();
try {
Dashboard result = apiInstance.addDashboard(requestParameters);
System.out.println(result);
} catch (ApiException e) {
System.err.println("Exception when calling DashboardsApi#addDashboard");
e.printStackTrace();
}

}

}