Magento 2.2: How to add a custom attribute in to Order?

Question

I have created a custom attribute of type customer_address and I would like to have the API to return me the value as an attribute when I call the API to receive an order.

Attribute:

private function upgradeExternalKeyAddressCustomer($customerSetup)
{
    $attributesInfo = [
        'mod_external_key'  => [
            'label' => __('External Key'),
            'type' => 'varchar',
            'input' => 'text',
            'position' => 200,
            'visible' => 1,
            'required' => 0,
            'system' => 0,
        ],
    ];

    foreach ($attributesInfo as $attributeCode => $attributeParams) {
        $customerSetup->addAttribute('customer_address', $attributeCode, $attributeParams);
    }

    foreach ($attributesInfo as $attributeCode => $attributeParams) {

        $attribute = $customerSetup->getEavConfig()->getAttribute('customer_address', $attributeCode);
        $attribute->setData(
            'used_in_forms',
            ['adminhtml_customer_address', 'customer_address_edit', 'customer_register_address']
        );
        $attribute->save();
    }
}

How to do this?

Answer 1

try this blog it will return your custom attribute in order api response https://www.atwix.com/development/adding-custom-attribute-to-api-response-in-magento-2/