How can I export the data in Xlxs format in Angular and i want to export the data such that the first row will be in Bold format?

// I want to download the above sheet in xlxs format in which the first row should be bold/

async downloadReport(): Promise<void> {const sheets = [];const dataRows = [];const payload = this.payloadService.payload['Journey1'];let response: any = this.reasonItems;response = [...new Map(response.map((item) => [item.sortData, item])).values()];

for (let i = 0; i < response.length; i++) {dataRows.push({'Column 1': response[i].data.barText,'Column 2': response[i].data.barData,'Column 3': '','Column 4': '','Column 5': '',});

for (let j = 0; j < response[i].top5.length; j++) {
  dataRows.push({
    'Column 1': '',
    'Column 2': '',
    'Column 3': response[i].top5[j].NotApprovedCpt,
    'Column 4': response[i].top5[j].text,
    'Column 5': response[i].top5[j].value,
  });
}
}

const sheetTitle = 'Sheet Title';sheets.push({ title: sheetTitle, data: dataRows });

const filters = {Timeperiod: filter1.timePeriod,Tin: payload.filter2.value || this.key,Npi: payload.filter3.value || this.key,Lob: payload.filter|| this.key,Channel: payload.channel || this.key,ServiceType: payload.serviceSetting || this.key,ServiceCategory: payload.ServiceCategory || this.key,};

this.downloadService.download({ sheets },{fileFormat: '.xlsx',fileName: 'abc',journeyName: 'def',metricName: 'ghi',filters,});}