How to figure out the body structure of a REST request job?

Question

I'm trying to transform Talend jobs to Spring Boot REST services. But I can't figure out the body of this post request.

Job 1 picture illustrates a JSON extract, and subjob picture is other in loop JSON extract, so I suppose the expected JSON is something like this:

{
    "user": "alvaro",
    "flight": [
        {
            "flightUID": "1",
            "infoSusp": "xx",
            "medSusp": "otr aprueba"
        },
            {
            "flightUID": "2",
            "infoSusp": "xx",
            "medSusp": "otr aprueba"
        }
    ]
}

But I always receive bad request response.

Job 1:

Subjob 2: