How to add items to the cart from different html pages using JavaScript and JQuery

I have three html pages with different products. I am using local storage and looping over the products using the button index. It was all good until I realized that when I click the button from another page it takes index one again and displays the first item from the object again. Please tell me a way to integrate all my pages together so the desired items are displayed in the cart. Here is some JS code that I am using.

            for(let i=0; i< carts.length; i++) {
carts[i].addEventListener('click', () => {
     cartNumbers(products[i]);
     totalCost(products[i]);


}); }

          function displayCart() {
let cartItems = localStorage.getItem('productsInCart');
cartItems = JSON.parse(cartItems);

let cart = localStorage.getItem("totalCost");
cart = parseInt(cart);

let productContainer = document.querySelector('.products');

if( cartItems && productContainer ) {
    productContainer.innerHTML = '';
    Object.values(cartItems).map( (item, index) => {
        productContainer.innerHTML += 
        `<div class="product"><ion-icon name="close-circle" color="primary"></ion-icon><img src="Images/${item.tag}.jpg" />
            <span class="sm-hide">${item.name}</span>
        </div>
        <div class="price sm-hide">${item.price}</div>
        <div class="quantity">
            <ion-icon class="decrease" name="arrow-dropleft-circle" color="primary"></ion-icon>
                <span>${item.inCart}</span>
            <ion-icon class="increase" name="arrow-dropright-circle" color="primary"></ion-icon>   
        </div>
        <div class="total">${item.inCart * item.price}</div>`;
    });

    productContainer.innerHTML += `
        <div class="basketTotalContainer">
            <h4 class="basketTotalTitle">Basket Total</h4>
            <h4 class="basketTotal">${cart}</h4>
        </div>`

Here is my object:

let carts = document.querySelectorAll('.cart');



  let products = [ 
{
    name: "EMPOWERED WOMEN",
    tag: "1",
    price: 29.95,
    inCart: 0
},
{
    name: "WOMEN IN STEM",
    tag: "2",
    price: 30.95,
    inCart: 0
},
{
    name: "ROSIE THE RIVETER",
    tag: "3",
    price: 40.95,
    inCart: 0
},
{
    name: "FEMINIST FLOWERS",
    tag: "4",
    price: 29.95,
    inCart: 0
}, ];

Here is html for products1 page. Products2 html also has same css but diferent products.

      <div class="container" align="center"><br>
        <h1>FEMME T-SHIRTS</h1>
        <br><br>
        <table class="table" style="width:100%">
          <thead>

            <tr>
              <td align="center">
                <img src="Images/1.jpg"  class="thumbnail">
                <p>EMPOWERED WOMEN EMPOWER WOMEN</p>
                <p>$ 29.95 USD</p>
                <p><a class="btn cart px-auto">ADD TO CART</a>
                </p>


              </td>

              <td align="center" id="2">
                <img src="Images/2.jpg"  class="thumbnail">
                <p>WOMEN IN STEM</p>
                <p>$ 29.95 USD</p>
                <p><a class="btn cart px-auto">ADD TO CART</a>
                </p>


              </td>

              <td align="center">
                <img src="Images/3.jpg"  class="thumbnail">
                <p>ROSIE THE RIVETER</p>
                <p>$ 29.95 USD</p>
                <p><a class="btn cart px-auto" id="3">ADD TO CART</a>
                </p>