PayPal button is not showinf after shortcode

Hello,

I want to use paypal button on custom template page. I used shortcode [woocommerce_checkout] on my custom template page. Like that:
echo do_shortcode(‘[woocommerce_checkout]’);

But PayPal button is not showing.

I googled that and find out solution that didn’t work for me:
https://github.com/woocommerce/woocommerce-gateway-paypal-express-checkout/pull/665

I have changed 1 stroke in this file (line 463):
class-wc-gateway-ppec-cart-handler.php

From this:
$is_checkout = is_checkout() && 'yes' === $settings->mark_enabled && ! wc_gateway_ppec()->checkout->has_active_session();

To this:
$is_checkout = ( is_page_template('template-memberships.php') || is_page_template('template-search.php') || is_checkout() ) && 'yes' === $settings->mark_enabled && ! wc_gateway_ppec()->checkout->has_active_session();

I think that I should change something more. So the question is how enable paypal button on a custom page in [woocommerce_checkout]?