Google apps script: Replacement of document text with sheets values

I am working on a form that takes values and puts them in a spreadsheet. I want to take the values from that spreadsheet and use them as replacements in a sheet (with the intent of saving to .pdf, which I will learn next)

Here is a snippet of my code. I was expecting the values in the {{}} to be replaced with the values from the spreadsheet. It’s not happening though. It NAMES the document appropriately, but I think I’m using the wrong function call for the body.

function createNewGoogleDoc(){

const googleDocTemplate = DriveApp.getFileById('<myTemplateID>');
const destinationFolder = DriveApp.getFolderById('<myFolderID>');
const sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Form Responses 1');
const rows = sheet.getDataRange().getValues()

rows.forEach(function(row,index){
  if (index === 0) return; //using strict equality check to see if this is the header row. If so, pass.
  if (row[38]) return;//38
  const copy = googleDocTemplate.makeCopy(`${row[4]}`+''s Service Contract',destinationFolder);
  const doc = DocumentApp.openById(copy.getId())
  const body = doc.getBody().replaceText();
  //const friendlyDate = new Date(row[31]).toLocaleDateString();
  //const friendlyDate2 = new Date(row[32]).toLocaleDateString();

  body.replaceText(`{{Email}}`, `${row[1]}`);   <--- this here.