curl --request POST \
  --url https://api.paytsoftware.com/v1/contacts \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "administration_id": "<string>",
  "contacts": [
    {
      "contact_identifier": "<string>",
      "id": "<string>",
      "birth_date": "<string>",
      "call_phone_number": "<string>",
      "default_email_address": "<string>",
      "firstname": "<string>",
      "gender": [
        "female",
        "male",
        "male_female"
      ],
      "infix": "<string>",
      "invoice_email_address": "<string>",
      "invoice_cc_email_address": "<string>",
      "invoice_bcc_email_address": "<string>",
      "lastname": "<string>",
      "middlename": "<string>",
      "postal_address_street_1": "<string>",
      "postal_address_street_2": "<string>",
      "postal_address_postal_code": "<string>",
      "postal_address_city": "<string>",
      "postal_address_country_code": "<string>",
      "postal_address_region": "<string>",
      "prefix": "<string>",
      "reminder_email_address": "<string>",
      "reminder_cc_email_address": "<string>",
      "reminder_bcc_email_address": "<string>",
      "sms_phone_number": "<string>"
    }
  ]
}
'

{
  "code": "<string>",
  "message": "<string>"
}