How to parse an object passed by an AJAX?

I made an Ajax POST request into my Laravel function however i am facing this result:

<script> Sfdump = window.Sfdump || (function (doc) { var refStyle = doc.createElement('style')

This happens when i die and dump my data so as to see what i get from ajax request. I have this jquery method:

$.ajaxSetup({
    headers: {
        'X-CSRF-TOKEN': $('meta[name="csrf-token"]').attr('content')
    }

});

$('#save-person').on('click', function() {
    let first_name = $('#first_name').val();
    let middle_name = $('#middle_name').val();
    let third_name = $('#third_name').val();
    let family_name = $('#family_name').val();
    $.ajax({
        url: urlReq+"/api/employee/customize",
        type: "POST",
        data: {
            first_name: first_name,
            middle_name: middle_name,
            third_name: third_name,
            family_name: family_name,
        },
        cache: false,
        success: function(dataResult){
            console.log(dataResult);
            let data = dataResult;

            if(data.statusCode==200){
                $("#success").show();
                $('#success').html('Data added successfully !');                        
            }
            else if(dataResult.statusCode==201){
                alert("Error occured !");
            }
        }
    });
});

and on my php method i have this:

public function customize_store(Request $request){
    //dd($request->first_name);
    $input = $request->all();

    dd($input);

    return response()->json(['Person'=>$input]);
}

which result to <script> Sfdump = window.Sfdump || (function (doc) { var refStyle = doc.createElement('style'), rxEsc = /([.*+?^${}()|\[\]\/\\])/g, idRx =... but my input are also present there that looks like this:

#<span class=sf-dump-protected title="Protected property">parameters</span>: <span class=sf-dump-note>array:15</span> [<samp>
      "<span class=sf-dump-key>first_name</span>" => "<span class=sf-dump-str title="7 characters">Michael</span>"
      "<span class=sf-dump-key>middle_name</span>" => "<span class=sf-dump-str title="6 characters">Sangga</span>"
      "<span class=sf-dump-key>third_name</span>" => <span class=sf-dump-const>null</span>
      "<span class=sf-dump-key>family_name</span>" => "<span class=sf-dump-str title="7 characters">Smith</span>"

How would i extract those data so that i can persist it on my database?

Try this code.. check the URL, Routes on which you are sending your data..

public function addPersonData(Request $request){
     $save_person = new Person(); // Initialize your model here..
     $save_person->first_name = $request->get('first_name');
     $save_person->middle_name = $request->get('middle_name');
     $save_person->third_name = $request->get('third_name');
     $save_person->family_name = $request->get('family_name');
     $save_person->save();
     return 'ok';     
}