curl --request POST \
--url https://api.sandbox.iron.xyz/api/customers/<customer_id>/identifications \
--header 'X-API-Key: <your-api-key>' \
--header 'IDEMPOTENCY-KEY: <unique-request-id>' \
--header 'accept: application/json; charset=utf-8' \
--header 'content-type: application/json; charset=utf-8'