phpspreadsheet read and getting values using header (1st row value) - phpspreadsheet

Question

How can i get all values from excel using 1st row value
It's working for me using this commande $spreadSheetAry[$i][0], but i need it $spreadSheetAry[$i]["Tracking_Number"]
it's possible?
This is code example:
<?php
use Phppot\DataSource;
use PhpOffice\PhpSpreadsheet\Reader\Xlsx;
require_once 'DataSource.php';
$db = new DataSource();
$conn = $db->getConnection();
require_once ('./vendor/autoload.php');
$allowedFileType = [
'application/vnd.ms-excel',
'text/xls',
'text/xlsx',
'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
];
$targetPath = 'uploads/test.xlsx';
$Reader = new \PhpOffice\PhpSpreadsheet\Reader\Xlsx();
$header = ["Tracking_Number", "Referance"];
$spreadSheet = $Reader->load($targetPath);
$excelSheet = $spreadSheet->getActiveSheet();
$spreadSheetAry = $excelSheet->toArray();
$sheetCount = count($spreadSheetAry);
for ($i = 0; $i <= $sheetCount; $i ++) {
$TN = "";
if (isset($spreadSheetAry[$i][0])) {
$TN = mysqli_real_escape_string($conn, $spreadSheetAry[$i][0]);
}
$RF = "";
if (isset($spreadSheetAry[$i][1])) {
$RF = mysqli_real_escape_string($conn, $spreadSheetAry[$i][1]);
}
echo $TN." - ".$RF."<br/>";
}
?>
Excel example:
enter image description here