How to add ValueList in CAP CDS for a FIORI ELEMENTS App

I have a CAP project which has one table and is a respective OData service. I have created a list object FIORI ELEMENTS App, so first, it gives me all the records, and then there is a create button that will open a form to create a new record in that table.

Now in that form where I am filling the data, I want Add Courses fields to get a value list from an external service which I have already defined

how I achieve that,

thank you.