Using flask app builder, a ModelRestApi was registered and responds when browsed to. I would like to use this API to populate an AjaxSelectField, which uses the Select2AJAXWidget to add autocomplete and search functionality.

I created a model with a __bind_key__ that points to the external data. The Select2AJAXWidget widget seems to be using the WTForm AjaxSelect field. However no data is populated by the widget, even if I pass it the API url.

How can I verify that the data from the API is effectively bieng populated into the widget?