AEM Forms Web Service Integration

Hi,

In my system, I need to integrate with a web service to fetch values to be populated in a AEM Forms drop down.

Went through the following URL for the same and found that it discusses invokeWebService API and it is difficult for me to really perform the integration using the information presented here.

https://helpx.adobe.com/aem-forms/6-1/invoke-web-services-adaptive-forms.html .

Could you please send me a tutorial (step by step instructions) with a package to deploy and see web services integration?

Appreciate your support.

Thanks,

Rama.