Promise base property

I am working on bpmn-js-properties-panel.

I am trying to add some pre-populated properties for the startEvent in table format using TableEntryFactory

And I have added properties for startEvent by passing static data using PropertiesProvider same as in custom Proerties

But now I am trying to pass data which will be the ajax response. But request takes time and execution go out of it with the blank object.

For simplification,suppose I am trying to create select dropdown with dynamic data as

var entryFactory = require('bpmn-js-properties-panel/lib/factory/EntryFactory');
var is = require('bpmn-js/lib/util/ModelUtil').is;
if (is(element, 'bpmn:StartEvent')) {

  // here I am calling  ajax request and response is stored in tableObject.
  // this will something like below

    id: 'tables',
    description: '',
    label: 'Table Name',
    selectOptions: tableObject,
    modelProperty: 'table'


but before getting response execution goes out of it.

How to deal with such situation.
Please suggest me the better way to achieve this.

@Mrunal Have you achieve now?? I have some question

I got same situation as above.
please provide some example or suggestion.