addDoubleOptInData example

if ($data->get('accountType')) {
            $customer['accountType'] = $data->get('accountType');
        }

        if ($data->get('accountType') === CustomerEntity::ACCOUNT_TYPE_BUSINESS && !empty($billingAddress['company'])) {
            $customer['company'] = $billingAddress['company'];
            if ($data->get('vatIds')) {
                $customer['vatIds'] = $data->get('vatIds');
            }
        }

        $customer = $this->addDoubleOptInData($customer, $context);

        $customer['boundSalesChannelId'] = $this->getBoundSalesChannelId($customer['email'], $context);

        if ($data->get('customFields') instanceof RequestDataBag) {
            $customer['customFields'] = $this->customFieldMapper->map(CustomerDefinition::ENTITY_NAME, $data->get('customFields'));
        }

        $this->customerRepository->create([$customer], $context->getContext());

        $criteria = new Criteria([$customer['id']]);
        $criteria->addAssociation('addresses');