If you are trying to read data in from an Excel spreadsheet, you can possibly do it as below. You will have to adjust the references to your cell locations.
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
gTestIdPathWay = "G:\\Katalon Test Cases\\Data Files\\TestId RT-WP-003"
FileInputStream fis = new FileInputStream (gTestIdPathWay);
XSSFWorkbook workbook = new XSSFWorkbook (fis);
XSSFSheet sheet = workbook.getSheet("Sheet1");
// get customer name from cell A2
Row row = sheet.getRow(1);
Cell cell = row.getCell(0);
userName = cell.getStringCellValue();
// get item name, or upc, from cell A6
row = sheet.getRow(5);
cell = row.getCell(0);
tempReferenceName = cell.getStringCellValue();
// get the sales staff from cell A9
row = sheet.getRow(8);
cell = row.getCell(0);
gSalesStaff = cell.getStringCellValue();
fis.close();
If @bionel is correct and you are using the browser extension, Katalon Recorder, then the above code I posted is not possible. In your heading, you have Katalon Studio. Katalon Studio and Katalon Recorder are two separate applications.