Kirby REST Api via http in json format in Kirby 3

Hi, I need to provide data via json for external use. The client need this information to deliver his service.
The way I tried is via api with basicAuth. In the api plugin I only get access to info as empty sdtclass:
how can I access customized data in the api plugin like

Is there now with Kirby3 a new way or is best to follow @jevets?

Maybe this plugin can help:

Apart from the Kirby API and the Better Rest plugin, you can also provide data through custom API endpoints. Another option is to provide JSON through content representations or routes. Depends on your use case.

Don’t quite understand what you mean?

Sorry, maybe I dont’t understand the REST Api concept very well.
I just want to deliver a list of requested projects by the client customers in json format. (Customers can check there projects via fontend login). The client needs a list of all requested projects to deliver his service.

My Question is how to provide best just this certain info in json format for an authorized person?

You can use a route or a content representation.

using the you can easily retrieve a „secret“. like

the secret could be an encoded, salted string: md5('AnyS4lt'.date('Ymd')) easily created in php and js.

Thanks to all of you!
I have it now working via content representation and basic auth. The only thing is that it is not working with blade.