Custom field not exposed in ErrorResource domain exception

[devDzign]

Hello,

I am currently trying to follow the API Platform documentation to create a custom domain exception using #[ErrorResource].

My goal is to expose a custom field to API clients when an exception is thrown.

Here's my code:
`use ApiPlatform\Metadata\ErrorResource;
use ApiPlatform\Metadata\Exception\ProblemExceptionInterface;

#[ErrorResource]
class MyDomainException extends \Exception implements ProblemExceptionInterface
{
public function getType(): string
{
return '/errors/418';
}

public function getTitle(): ?string
{
    return 'Teapot error';
}

public function getStatus(): ?int
{
    return 418;
}

public function getDetail(): ?string
{
    return $this->getMessage();
}

public function getInstance(): ?string
{
    return null;
}

public string $myCustomField = 'I usually prefer coffee.';

}
`
However, when this exception is thrown and caught by API Platform, the myCustomField is not present in the JSON response. I expected it to be exposed in the output, but it is not.

Is there a way to make this custom property appear in the error response? Do I need to use serialization groups or a custom normalizer?

Thank you for your help!