AJAX Endpoint for Changing Payment Method Unavailable When addToCartByAjax is Disabled

[crookoo]

Bug Report

Current Behavior
When using the partial Cart/OrderForm/PaymentMethod.html, the payment method is set via AJAX. However, if the TypoScript constant addToCartByAjax is set to an empty value (addToCartByAjax =), the AJAX endpoint required for changing the payment method is no longer available. This prevents the payment method from being updated in step 3 of the checkout process.

Expected behavior/output
The payment method should still be changeable via AJAX in step 3, regardless of whether addToCartByAjax is enabled or not.

Environment

• TYPO3 version(s): 11.5.38
• cart version: 8.2.0
• Is your TYPO3 installation set up with Composer (Composer Mode): no
• OS: Windows 11

Possible Solution
Allow the AJAX endpoint for changing the payment method to remain available, even if addToCartByAjax is disabled.

Additional context
The behavior was noticed while implementing a multi-step checkout process. Please investigate this and provide a fix if possible.