According to Apple documentation, there's a bunch of buttons types available when using Apple Pay.
See them listed here: https://developer.apple.com/documentation/apple_pay_on_the_web/displaying_apple_pay_buttons (specially when using version 4 of Apple Pay we have the ability to use the standard Apple Pay button for enabling subscriptions: "Subscribe with...").
Summary
According to Apple documentation, there's a bunch of buttons types available when using Apple Pay. See them listed here: https://developer.apple.com/documentation/apple_pay_on_the_web/displaying_apple_pay_buttons (specially when using version 4 of Apple Pay we have the ability to use the standard Apple Pay button for enabling subscriptions: "Subscribe with...").
For a list of Apple Pay versions for the Web see: https://developer.apple.com/documentation/apple_pay_on_the_web/apple_pay_on_the_web_version_history
The button types supported by the
PaymentRequestButton
is actually very limited: https://stripe.com/docs/stripe-js/elements/payment-request-button#react-styling-the-elementIt's actually odd that it does support "Book" and doesn't support "Subscribe" as both seems to be available since version 4 of Apple Pay.