The developer can deal with this issue by modifying the admin path timeout value in seconds in the Fastly Configuration section > Advanced Configuration in the Admin Panel. Fastly is a cloud-based caching service that improves site performance and security for Adobe Commerce Cloud projects. Fastly has a default timeout value of 180 seconds for admin requests, which means that any request that takes longer than 180 seconds will be terminated and result in a timeout error. The developer can increase this value to allow longer processing time for admin requests without causing errors. The developer also needs to save the configuration and upload VCL to Fastly to apply the changes. Verified Reference: [Magento 2.4 DevDocs]

The developer should create an extension attribute on the Magento\Sales\Api\Data\OrderInterface interface and an after plugin on the Magento\Sales\Api\OrderRepositoryInterface::get() and Magento\Sales\Api\OrderRepositoryInterface::getList() methods.
The extension attribute will store the custom data. The after plugin will be used to add the custom data to the order object when it is fetched from the API.
Here is the code for the extension attribute and after plugin:
PHP
namespace MyVendor\MyModule\Api\Data;
interface OrderExtensionInterface extends \Magento\Sales\Api\Data\OrderInterface
{
/**
* Get custom data.
* * @return string|null
*/
public function getCustomData();
/**
* Set custom data.
* * @param string $customData
* @return $this
*/
public function setCustomData($customData);
}
namespace MyVendor\MyModule\Model;
class OrderRepository extends \Magento\Sales\Api\OrderRepositoryInterface
{
/**
* After get order.
* * @param \Magento\Sales\Api\OrderRepositoryInterface $subject
* @param \Magento\Sales\Api\Data\OrderInterface $order
* @return \Magento\Sales\Api\Data\OrderInterface
*/
public function afterGetOrder($subject, $order)
{
if ($order instanceof OrderExtensionInterface) {
$order->setCustomData('This is custom data');
}
return $order;
}
/**
* After get list.
* * @param \Magento\Sales\Api\OrderRepositoryInterface $subject
* @param \Magento\Sales\Api\Data\OrderInterface[] $orders
* @return \Magento\Sales\Api\Data\OrderInterface[]
*/
public function afterGetList($subject, $orders)
{
foreach ($orders as $order) {
if ($order instanceof OrderExtensionInterface) {
$order->setCustomData('This is custom data');
}
}
return $orders;
}
}
Once the extension attribute and after plugin are created, the custom data will be added to orders fetched from the API.

The command used to upgrade ECE-Tools on an Adobe Commerce Cloud platform is composer update magento/ece-tools --with-all-dependencies. This command will update the ECE-Tools package and its dependencies to the latest version available in the composer repository. The developer then needs to commit and push the changes to the composer.json and composer.lock files and redeploy the environment. Verified Reference: [Magento 2.4 DevDocs]

The input_type attribute of a product EAV attribute specifies the type of input field that will be used to enter the value of the attribute in the admin panel. The textarea input type is used for WYSIWYG fields. If the input_type attribute is not set to textarea, then the attribute will not appear as WYSIWYG in the admin panel.
To fix this, the developer should set the input_type attribute to textarea.