Please note: This functionality only works for Shopify Plus plans and above.
1. Customer key from the FlavorCloud app
First, you will need to copy your customer key from the FlavorCloud app in the “API” section:

2. Replace your customer key in the script
Replace your customer key in the last script tag (highlighted in yellow below).
Then, add all of the following script tags in your checkout.liquid file:
<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-cookie/1.4.1/jquery.cookie.min.js" integrity="sha512-3j3VU6WC5rPQB4Ld1jnLV7Kd5xr+cq9avvhwqzbH/taCRNURoeEpoPBK9pDyeukwSxwRPJ8fDgvYXd6SkaZ2TA==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
<script src="https://partnerapi.flavorcloud.com/Customers/shopify-checkout-script?CustomerKey=<custKey>"</script>
Once you have added your customer key to the script tag, copy the three script tags and paste them into your Shopify store’s checkout.liquid file in the Layout folder, like the following:

4. Finished
After you have saved the edits in the checkout.liquid file, then you are done!