Help to finish creating the extension

Hi, so I’m having two difficulties finishing an extension.

The first is knowing how to create an “API Key” property, just like Airtable.

And the second is how do I get the return of a list

List<String> genres = new ArrayList<>();
 try {
  JSONArray jsonArray = json.getJSONArray("genres");
    for (int i = 0; i < jsonArray.length(); i++) {