How to update the header in papaparse unparse

How to apply the header name in csv. cause when I try to export the csv. the header applying is the key instead the header name.

current output
id, firstName, lastName, sampleLocation

`export default function useReports() {
  const COLUMNS = (reportColumns);

  const process = async (data = {}) => {
    const excel = useExcelExport();
    const workbook = excel.workbook;
    const sheet = excel.addWorksheet(workbook, 'Sheet 1', false);
    const today = format(new Date(), 'yyyyMMdd');

    // Page setup
    sheet.pageSetup.margins = {
      left: 0.25,
      right: 0.15,
      top: 0.5,
      bottom: 0.25,
      header: 0.25,
      footer: 0.25
    };

    const cols = COLUMNS.map(a => ({
      key: a.field,
      header: a.headerName,
      width: 15
    }));

    sheet.columns = cols;

    const csvData = [];
    data['items'].forEach(item => {
      const obj = {};

      cols.forEach(col => {
        obj[col.key] = item[col.key];
      });

      dateFields.forEach((field) => {
        try {
          if (obj[field]) {
            obj[field] = obj[field] ? format(new Date(obj[field]), 'dd-MM-yyyy') : ''
          }
        } catch (e) { }
      });

      if (data['type'] === 'csv') {
        csvData.push(obj);
      }
      sheet.addRow(obj);
    });

    if (data['type'] === 'xslx') {
      excel.setBorder(sheet, '333333');
      excel.saveExcel(workbook, `Report'${today}`)
    } else if (data['type'] === 'csv') {
      const csv = Papa.unparse(csvData);
      excel.saveCSV(csv, `Report'${today}`);
    } else {
    }
  }`

I try to apply this

const csvHeaders = cols.map(col => col.header);
      const csv = Papa.unparse({
        fields: csvHeaders,
        data: csvData
      });

but the header was update but no data display. cause the field key not same.