I am trying to add a product to a shopping cart in mongodb but the code I have written does not work. I have set up and if statement to check if the selected product’s id is included in the items array and if true to console.log(‘match found’); within this if statement is also where my code that is not working is set up. Can you show me a better way to update the product quantity instead of whats it’s doing now which is just adding the same product to cart in mongodb.

const express = require('express');
const Carts = require('../repo/carts');

const router = express.Router();

router.post('/cart/products', async (req, res) => {
  Carts.findById(req.session.cartId, (err, foundCart) => {
    if (err) {
      console.log(err); // This err is for the find by Id, not to the update function
    }
    if (foundCart) {
      console.log(foundCart);
      console.log(req.body.productId);

      let check = foundCart.items.map((item) => item.id);
      // console.log(check);
      //THE CODE BELOW IS WHERE ISSUE OCCURS
      if (check.includes(req.body.productId)) {
        console.log('MATCH FOUND');
        Carts.updateOne(
           {_id: req.body.productId },
           { $inc: {  quantity: 1 } }
        );
      }

      Carts.updateOne(
        { _id: foundCart._id },
        {
          $push: {
            items: {
              _id: req.body.productId,
              quantity: 1,
            },
          },
        },
        (err, updatedCart) => {
          if (err) {
            console.log(err);
          }
        }
      );
    } else {
      if (!foundCart) {
        const newCart = new Carts({
          _id: req.session.cartId,
          items: [],
        });
        newCart.save();
      }
    }
  });

  res.send('product added to cart!!');
});

module.exports = router;

example of the array

 items: [
    { quantity: 1, _id: '6356ffb3ece7e49784bfbd5d' },
    { quantity: 1, _id: '6356ffb3ece7e49784bfbd5d' },
    { quantity: 1, _id: '6356ff91ece7e49784bfbd5a' },
    { quantity: 1, _id: '6356ff75ece7e49784bfbd57' },
    { quantity: 1, _id: '63570003ece7e49784bfbd69' },
    { quantity: 1, _id: '63570003ece7e49784bfbd69' },
]