Shopify has express checkout buttons to help you increase sales as it provides the customer an easier way to pay. But while using Product Personalizer you face may an issue where the express checkout buttons are not showing on the checkout page.
The reason behind the problem:
Shopify tracks the user’s activity using cookies. So if a user customizes a product and then clicks on add to cart and then goes to the add to cart page the express checkout buttons will show up on the cart page. And if the user has already seen the express checkout button on the cart page it will not show up on the checkout page anymore. Shopify remembers it through cookies. But if a user directly goes to the checkout page skipping the cart page the express checkout button will show up on the checkout page.
If you are facing an issue where the express checkout button is not showing up in the checkout page the reason behind is the user is seeing it on the cart page, as we discussed in the earlier section. So if you want to show the express checkout buttons on the checkout page you need to prevent the user from going to the cart page.
You can do that by going to Product Personalizer -> Settings -> Action after a product is added to the cart -> Stay on the product page and show a success message
Make sure you have cleared your browser cache after enabling this option. Thanks!