Can not click add to cart or Buy it now

I have almost 18 Sku, but when I click any of them, (on my phone), it is not work. I can click on my laptop.

where I should troundleshooting first???

https://meetshoppy.com/products/case-for-iphone-random-style

  1. In your Shopify Admin go to online store > themes > actions > edit code
  2. In your theme.liquid file, find the (press CTRL + F or command + F on Mac)
  3. paste this code right above the tag:
<script>
    function addToCartMobileClick() {

if (!/product/.test(window.location.href)){
return;
}

        var btn = document.querySelector(`#mst-stiky-box button`);

btn.addEventListener('click', function(){
var atc = document.querySelector(`.grid__item.row_grid_qnt button`);

atc.click();
});
    }

addToCartMobileClick()
</script>

Copy

Please let me know whether it works.

Kind regards,
ThePrecisionist