I have created customer address attribute "city_id" with setup script. I am able to save the value. but want to display the city_id field to the below apis json response. how we can we add city_id in the response for existing apis?
GET /V1/carts/mine/billing-address GET /V1/guest-carts/:cartId/billing-address
I found one reference link https://web4pro.net/blog-news/magento-2-add-custom-attribute-customers-address/ and is this suitable for this requirement?