Create a customer

curl --request POST \
  --url https://dev.flextell.ai/api/v1/customers \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "first_name": "<string>",
  "last_name": "<string>",
  "phone_number": "<string>",
  "email": "jsmith@example.com",
  "date_of_birth": "2023-11-07T05:31:56Z",
  "gender": "male",
  "country_id": 123,
  "identity_number": "<string>",
  "job": "<string>",
  "address": "<string>",
  "default_channel_id": 123,
  "user_id": 123
}
'

{
  "success": "<string>",
  "data": {
    "id": 123,
    "first_name": "<string>",
    "last_name": "<string>",
    "phone_number": "<string>",
    "email": "<string>",
    "date_of_birth": "2023-11-07T05:31:56Z",
    "gender": "male",
    "country_name": "<string>",
    "identity_number": "<string>",
    "job": "<string>",
    "address": "<string>",
    "default_channel_id": 123,
    "avatar_url": "<string>",
    "related_user": {
      "id": 123,
      "name": "<string>"
    },
    "created_at": "2023-11-07T05:31:56Z",
    "updated_at": "2023-11-07T05:31:56Z",
    "deleted_at": "2023-11-07T05:31:56Z"
  }
}