The following code snippets in the Checkout API Setup Guide at
https://docs.connect.squareup.com/payments/checkout/setup references GetID()
cause the page to fail and are not in the API:
$checkoutId = $result->getId();
AND
$checkoutUrl = $result->getCheckoutPageUrl();
In fact, I cannot find reference to those commands anywhere in the technical docs or API reference except on the Setup Guide.
Is the Setup Guide wrong or am I missing something? Is Checkout not fully live? I am not sure why a setup example would not be more supported or reference existing documentation.
Update: In the file provided with the SDK, the file Checkout.md describes that getId() and getCheckoutPageUrl() are getters for protected properties:
Note: All properties are protected and only accessed via getters and setters.
I get that... they just don't seem to work.