How to send custom emails from a spreadsheet using google apps script.

emailAutomation.js

function createDocument(name, email, position, status){
  //get the email template from google doc using the url of the file
  const templateUrl = 'https://docs.google.com/document/d/1sRHXLlb3nsaiGVodhPNdt0SeYE1Gy-UnB4HQ1r2Wn-8/edit'
  
  //Get that template
  const template = DocumentApp.openByUrl(templateUrl)
  
  // Extract the text in the body of the documemt
  const text = template.getBody().getText()

  //Replace all placeholders
  const emailBody = text.replace('#Name', name)
              .replace('#position', position)
              .replace('#status', status)
  
  
  MailApp.sendEmail(
    email,
    'Response to Job Application',
    emailBody
  )
}

function sendEmails() {
  //get the spreadsheet with the emails
  const emialSpreadsheet =  SpreadsheetApp.getActiveSpreadsheet().getActiveSheet()
  
  //get all data inside the spreadsheet
  const data = emialSpreadsheet.getDataRange().getValues()

  //Iteriate through the data
  data.forEach((applicant, index) => {
    if (index > 0) //Skips the first array which is the header
    {
      createDocument(...applicant)
    }
  })

  SpreadsheetApp.getUi().alert('ALL Emails have been sent') //Show an alert on google sheet that the mails have been sent.
}