How do I redirect to a different page from this function nodejs

Question

I need help redirecting after I submit this order. Basically everything is working but after the order is saved I can't figure out how to redirect the view. I would like to just redirect to the index which is at "/" but everything I've tried doesn't work. Any tips would be greatly appreciated.

app.post('/postOrder/:id', function(req, res, next){
  var customerInfo = req.body.info;
  var packageInfo = req.body.items.items;
  var storeID = req.params['id']
  let ts = Date.now();
    let date_ob = new Date(ts);
    let date = date_ob.getDate();
    let month = date_ob.getMonth() + 1;
    let year = date_ob.getFullYear();

let yourOrder = []

packageInfo.forEach((package) => cusOrder(package.product, package.qty));  

function cusOrder(product, qty){
  let order = {product: product, qty: qty}
  yourOrder.push(order);
}

console.log(yourOrder);
  const order = {
      package: yourOrder,
      storenum: storeID,
      date: year+"/"+month+"/"+date,
      first: customerInfo[0].fname,
      last: customerInfo[1].lname,
      address: customerInfo[2].address,
      city: customerInfo[3].city,
      state: customerInfo[4].state,
      zipcode: customerInfo[5].zip
    }
   Orders(order).save()
}

);