Create a function named cartproducts that takes in the product productid as an argument

/* Create a function named cartProducts that takes in the product productId as an argument

cartProducts should get the correct product based on the productId
cartProducts should then increase the product's quantity
if the product is not already in the cart, add it to the carty array */
/////////////////////////

<pre lang="Javascript">let products = [
      {
        name: "juice",
        price: 2.50,
        quantity: 500,
        productId: 1,
      },
    
      {
        name: "water",
        price: 2.50,
        quantity: 1000,
        productId: 2,
      },
    
      {
        name: "milk",
        price: 1,
        quantity: 5000,
        productId: 3
      },
    ];
    
    const carty = [];

function addProductToCart(productId){} but im not sure what to go from, tried everything but cant seem to work