Read local XLSX file and edit it in React

Question

I am using ExcelJS library in React to read a local XLSX file. My motive is to read the template.xlsx file from local, in the same directory and modify it as needed and download it using saveAs library.

Following is the code that I am following right now:

import ExcelJS from 'exceljs';
import { saveAs } from 'file-saver';

export async function generateExcelReport() {
  try {
    const workbook = new ExcelJS.Workbook();
    await workbook.xlsx.readFile('template.xlsx');
    const worksheet = workbook.getWorksheet('Sheet1');
    const cellC2 = worksheet.getCell('C2');
    cellC2.value = 'New Value';
    const blob = await workbook.xlsx.writeBuffer();
    saveAs(new Blob([blob]), 'modified_template.xlsx');
  } catch (error) {
    console.error('Error generating the report', error);
  }
}

But I am unable to read the file, is it true that we would need a FileReader on the client side to read the files? What is the best way to do this?