How to implement handlers to render my own data with Search UI

I worked through the Elastic Search UI on github and finally found what I need, to render my own data:

It seems like I can implement a handler, that takes the search query, so that I can send it to my API and render my json file. I did implement it like that within the config constant:

import myData from './data.json';
apiConnector: connector,
onSearch: async state => {
    return myData;

Indeed, my json file is rendered. Actually, as a test, myData is a json file that contains the same national parks as in the example. However, I cannot use the functionality of the Search UI anymore, that means I cannot apply filters, sort by title/relevance or anything. How can I fix that?

Thank you for your help!