how to set different font sizes within in a cell

$rowIndex = 1;
foreach ($request->warehouses as $warehouse) {
    $whId = $asset['id_fixed_asset'];
    $warehouse = Warehouse::find($whId);
    if ($warehouse) {
            foreach ($rowDetails as $rowDetail) {
                $fieldName = $rowDetail['id_field'];
                $fieldValue = $warehouse->$fieldName;
                $fontSize = $rowDetail['font_size'];
                $cellData = "$fieldValuen";
                $sheet->setCellValue('A' . $rowIndex, $cellData);
                $sheet->getStyle('A' . $rowIndex)->getAlignment()->setWrapText(true);
                $sheet->getStyle('A' . $rowIndex)->getFont()->setSize($fontSize);
                
                $rowIndex++;
            }
        
    }
}

In this code, field_value has a different font_size and is separated in each cellresult

i want to make an export excel file with format where each field_value has a font_size value that has been set and the field_values are separated by a new line in the cell (wrap text), while the new data from each fixed_asset will be separated in a new cell. For example like this:
expectations