Shopify Add to cart

add-to-cart.js

document.addEventListener("DOMContentLoaded", function() {
    const forms = Array.from(document.querySelectorAll("form.add_to_cart"));
    forms.forEach(form => {
        form.addEventListener("submit", e => {
            e.preventDefault();
            const button = form.querySelector("button");
            const product_id = button.dataset["prod-id"];
            fetch("/cart/add.js", {
                method: "POST",
                headers: {
                    "Content-Type": "application/json"
                },
                body: JSON.stringify({ quantity: 1, id: product_id });
            })
                .then(resp => resp.json())
                .then(data => {
                    document.querySelector(".cart-count").textContent =
                        data.cart.count;
                })
                .catch(err => {
                    alert(
                        "Oops! Something went wrong. Please try to add your product again. If this message persists, the item may not be available."
                    );
                });
        });
    });
});