src/Publisher.php
public function submitAttachment(string $idArticle, Model $attachment, string $field): array
    {
        return json_decode(
            $this->post(
                $this->getAttachmentEndPoint($idArticle, $field),
                $this->normalizePayload(
                    $attachment->getCollection()
                )
            ),
            true
        );
    }
public function submitAttachment(string $idArticle, Model $attachment, string $field): array
    {
        return json_decode(
            $this->post(
                $this->getAttachmentEndPoint($idArticle, $field),
                $this->normalizePayload(
                    $attachment->getCollection()
                )
            ),
            true
        );
    }
submit each attachment of an article here