Ryder here, from the Social Care Team at Shopify. Welcome to the Community and thanks for posting! Some accelerated checkout methods can use dynamic checkout buttons on product pages, and it sounds like you've already enabled Apple Pay as an accelerated checkout.
Since you already have a third-party accelerated checkout method, you can add other accelerated checkout options as branded dynamic checkout options through your Theme Editor. Please keep in mind that dynamic buttons will change to reflect the customer's preferred accelerated checkout method.
In your Admin, go to Online store > Themes and clicking Customize next to the theme you're wanting to add these options to. From there, how you add them will depend on where on your store you'd like them displayed. The button will then dynamically change to reflect the customer's preferred accelerated checkout method. After you've set it up, don't forget to test your dynamic checkout buttons!
As the button that appears to customers is entirely dependent, these key factors are worth taking into consideration:
I hope this helps. Please let me know if there's anything I can clarify.