How to expose filter for entity reference as dropdown in the Search API view? In my Search API view, I'd like an Exposed filter > Entity reference to be a select box, not a text field.

Details

I have a view which I created like:


Views > Add new view > Show: default node index


So it uses the Search API index as a basis.

In the Search API I have ticked to index field_entity which is an Entity reference &gt; Content_type: entity (confusing naming, I know).

I want the user to go to the views page &amp; be able to filter the view results by field_entity (which is an exposed filter/entity reference). 

The issue is the view shows the exposed filter as a text field. I have edited field_entity &amp; checked the box Render Views filters as select list - this works fine for a normal view but not for a Search API view. 

Question

Can I somehow convert this text field to a select box?



To clarify, I cannot use custom or contributed modules on this project, so it needs to be done without using hooks, or other modules, etc.
Try to use TYPE => String. This work for me.