Enable Express Checkout (Apple Pay/Google Pay) on custom checkout template

I’m struggling with an issue that I can’t seem to resolve.

I have a WooCommerce site using the official Stripe plugin with Express Checkout enabled (Apple Pay, Link, and Google Pay). However, my checkout is not the default WooCommerce checkout nor the one from Storefront—it’s a custom template that essentially includes the following:

get_header();
$checkout = WC()->checkout();
do_action('woocommerce_before_checkout_form', $checkout);
woocommerce_order_review();
do_action('woocommerce_checkout_before_customer_details');
do_action('woocommerce_checkout_shipping');
do_action('woocommerce_checkout_billing');
do_action('woocommerce_checkout_order_review');
do_action('woocommerce_after_checkout_form', $checkout);
get_footer();

Setup details:

• I have a file called page-checkout.php with the above code.
• In WordPress, I created a page with the slug checkout and set it as the checkout page.
• Everything in Stripe and the Stripe plugin is up-to-date and correctly configured.

The issue:

The Express Checkout buttons (Apple Pay, Link, Google Pay) do not appear anywhere.

• If I replace my custom hooks with the_content() and use the [woocommerce_checkout] shortcode in the page content, the buttons still don’t show.
• The only way I can get Stripe to display Express Checkout is by using WooCommerce’s official Gutenberg checkout block:

But obviously, this is not a viable solution for me since it’s incompatible with my custom checkout template.

Does anyone know how to properly enable Express Checkout on a fully custom checkout page? Or is the Stripe plugin hardcoded to work only with the Gutenberg checkout block?

Any help would be greatly appreciated!