Trouble in populating checkbox dynamically

Hi All,

I need to populate the checkbox dynamically based on values returned by the service call in AEM FORMS 6.4.

I have refered below AEM 6.5 link:

https://docs.adobe.com/content/help/en/experience-manager-learn/forms/adaptive-forms/choice-group-items-adding-dynamically-article.html

But it is not working as shown in the example.

Is there any other similar way to populate it?