How to send Ajax query with JQuery (Search API - Request Body) to Elasticsearch server

Hello,

I want to perform an Ajax request to elasticsearch server in both forms: through
search api - URI request and Request Body.

For the first case the request looks like this:

...

The above request works, but i would like to know how can I send request by
using the search API - request body. Can anyone give me a complete sample, for
dummies?

I have tried something like this, but it doesn't work:

Thank you in advance!