Excel Formulas are not working after using it with exceljs

currently I am working on a project where I need to put a certain value to a certain field in a excel file I am doing that by using exceljs but after putting the value the result amount should be according to the given calculations which is not happening I am updating the code please have a look and help me

const express = require('express')
const router = express.Router()
const Excel = require('exceljs')
const writeFile = async (salary) => {
    const filename  = 'public/Guatemala_2022_Tax_File.xlsx'
    const output = 'public/output.xlsx'
    const workbook =  new Excel.Workbook()
    await workbook.xlsx.readFile(filename)
    var worksheet = workbook.getWorksheet("Sheet1")
    const row = worksheet.getRow(2)
    row.getCell('B').value = salary
    await workbook.xlsx.writeFile(output);
}
router.post('/excel', async(req,res) => {
    await writeFile(req.salary)
    const newWorkbook = new Excel.Workbook();
    await newWorkbook.xlsx.readFile('public/output.xlsx');
    const newworksheet = await newWorkbook.getWorksheet('Sheet1');
    console.log('k2 value',newworksheet.getCell('K2').value)
    res.json(newworksheet.getCell('K2').value)
})

module.exports = router

this is the code

thanks in advance