I have a static HTML and JS website with a shopping cart where its functionality is carried out using JS and Jquery. I need to pass my cart values to Shopify and take the user directly to the Shopify Checkout page when user clicks on the checkout button on my site. I need to pass cart values to Shipify and load the checkout page on the browser. How can I do this? I'm new to Shopify and I need some guidance on how to do this.