Show the returned error from php file in jquery Ajax

i am trying to get data via ajax. everything works fine except the "error handler". whenever i have error in my php i want that the error is sent to the html page (javascript file). it’s not working.

im using the success in my ajax.

What i want is to get alerted with the msg and error ive set in the PHP file (line 5 and 6)

Here is my code:

PHP

$result = mysqli_query($conn, $sql);

if (!$result || mysqli_num_rows($result) == 0) {
$resp = array(
    'status' => "Error",
    'msg'    => "Error Msg",
    'error'  => mysqli_error($conn)
);
echo json_encode($resp);
die();
} else {

while ($row = mysqli_fetch_array($result)) {
    $id = $row['id'];
    // $ownId = $row['own_id'];
    $name = $row['name'];
    $geraet = $row['manuf'].' '.$row['model'];
    $fail = $row['fail'];
    $abg_dat = $row['pick_date'];
    $status = $row['status'];

    $return_arr[] = array("id" => $id,
                    "name" => $name,
                    "geraet" => $geraet,
                    "fail" => $fail,
                    "abg_dat" => $abg_dat,
                    "status" => $status
                );
}
$resp = array(
    'status' => "Succ" ,
    'msg'    => "Daten erfolgreich abgerufen",
    'resp'   => $return_arr
);

echo json_encode($resp);
}

JS

$.ajax({
    url: `${phpDir}/inc/techniker.inc.php`,
    type: 'get',
    dataType: 'JSON',
    success: function(response){
        if (response['status'] == "Error") {
            alert(response['status'] +  "<br/>" + response['error']);
            
        } else {
            var len = response['resp'].length;
            var rspKey = response['resp'];
            for(var i=0; i<len; i++){
                var id = rspKey[i].id;
                var name = rspKey[i].name;
                var geraet = rspKey[i].geraet;
                var stoerung = rspKey[i].fail;
                var abgabe = rspKey[i].abg_dat;
                var status = rspKey[i].status;
                // example on muliple rows
                // var username = response[i].username;
                
                var tr_str = `
                <tr id="${id}" onclick="tabCaller(${id})">
                    <td>#${id}</td>
                    <td>${name}</td>
                    <td>${geraet}</td>
                    <td>${stoerung}</td>
                    <td>${abgabe}</td>
                    <td>${status}</td>
                </tr>
                `;
                $("#techniker_tbody").append(tr_str);
            }
        }
    }
});

UPDATE
when mysqli error is happening the php is breaking and showing the error before he sends the response. that why im not gettin the ‘error’ either the ‘msg’