Julie here from Shopify Support. Thanks for the link to your store, as well as the screenshots. This is a great question.
While PayPal refers to these as "smart payment buttons", Shopify offers "dynamic checkout buttons", which are quite similar. Dynamic checkout buttons are displayed on your product pages and dynamically change to reflect the customer's preferred accelerated checkout method, which is quite often PayPal.
Much like smart payment buttons, dynamic checkout buttons offer the customer the ability to pay with PayPal directly from the product page. However, while PayPal's smart payment buttons also display "Credit or Debit" as options, Shopify's dynamic checkout buttons instead include a "More payment options" button, which will take customers directly to the Shopify checkout, where they can proceed with a credit card transaction.
Taking a look at your product pages, it appears that you already have dynamic checkout buttons enabled. For example, this is what I see when I head to one of your product pages:
Is the reason why you're wanting to have PayPal's smart payment buttons because you'd like to give customers the ability to pay with credit or debit through the PayPal gateway? With PayPal Express, the default is set to ask customers to log in to PayPal (or create a PayPal Account). However, you can enable guest payments to let customers pay with their credit card even if they don't have their own PayPal account. To enable guest payments, you'll just need to change the settings in your PayPal account settings. Feel free to check out PayPal's help doc on enabling guest payments to learn more.
If you are still wanting to add PayPal's smart button, then I would recommend getting in touch with a Shopify Expert to see if this is possible. Because Shopify themes are built upon a different code language, Liquid, the process for integrating this likely involves more than just simple HTML. I'm also curious to see if the rest of the Community has any suggestions.
I hope this clears things up and helps explain the similarities and differences between PayPal's smart buttons and Shopify's dynamic checkout buttons. If I've misunderstood your question, or if you have any followup inquiries, please feel free to respond here!
im about to get really annoyed by shopify services, all i see are promises for the future without any action taken.
What can be so hard about letting customers implement simple HTML code in order to let customers pay with credit-card?
It's the least you can do since the proposed payment-providers dont reply at all or after a couple of weeks.
By the end of my subscription, i highly doubt that i will renew my shopify plan. Cannot reccomend