Cannot add metadata to stripe online payments

I am trying to create metadata during the object creation process but could not do it. Here is my code

router.post("/create-checkout-session", async (req, res) => {
  let line_items = req.body.cart.map((e)=>{
    return {
      price_data: {
        currency: "usd",
        product_data: {
          name: e.title,
          description: e.desc,
          images: [e.images],
          metadata: {
            id: e.id,
          },
        },
        unit_amount: e.price,
      },
      quantity: e.quantity,
    };
  })
  const session = await stripe.checkout.sessions.create({
    line_items,
    mode: "payment",
    success_url: `${YOUR_DOMAIN}/`,
    cancel_url: `${YOUR_DOMAIN}/cart`,
  });
  res.send({ url: session.url });
});

I can see all my data on the stripe dashboard other than metadata.

In your request, the metadata is set under product_data field which will only be stored under Product object. Metadata on ad-hoc Product object isn't shown in the Dashboard, but it can be retrieved via Retrieve Checkout Session API with expanding line_items.data.price.product field. For example,

const session = await stripe.checkout.sessions.retrieve('cs_xxx', {
  expand: ['line_items.data.price.product',],
});

The dashboard you check the payment is Payment Intent object. Metadata doesn't get populated from one object to another, i.e. metadata on Product object won't be populated to Payment Intent object. If you wish to have metadata shown in Payment Intent object, the metadata should be set under payment_intent_data.metadata field. For example,

const session = await stripe.checkout.sessions.create({
  line_items: [
    {
      price_data: {
        currency: 'usd',
        product_data: {
          name: 'T-shirt',
        },
        unit_amount: 2000,
      },
      quantity: 1,
    },
  ],
  payment_intent_data: {
    metadata: {
      order_id: 'order_123',
    },
  },
  mode: 'payment',
  success_url: 'http://localhost:4242/success',
  cancel_url: 'http://localhost:4242/cancel',
});