curl --request POST \
  --url https://{space}.{region}.api.niadra.com/v1/identity/assertions \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'Idempotency-Key: <idempotency-key>' \
  --data '
{
  "handles": [
    {
      "type": "phone_e164",
      "value": "+14155550123"
    },
    {
      "type": "system_id",
      "value": "48213",
      "scope": "crm"
    }
  ],
  "method": "system_import",
  "subject_kind": "person",
  "reason": "CRM contact record 48213"
}
'

import requests

url = "https://{space}.{region}.api.niadra.com/v1/identity/assertions"

payload = {
    "handles": [
        {
            "type": "phone_e164",
            "value": "+14155550123"
        },
        {
            "type": "system_id",
            "value": "48213",
            "scope": "crm"
        }
    ],
    "method": "system_import",
    "subject_kind": "person",
    "reason": "CRM contact record 48213"
}
headers = {
    "Idempotency-Key": "<idempotency-key>",
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {
    'Idempotency-Key': '<idempotency-key>',
    Authorization: 'Bearer <token>',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    handles: [
      {type: 'phone_e164', value: '+14155550123'},
      {type: 'system_id', value: '48213', scope: 'crm'}
    ],
    method: 'system_import',
    subject_kind: 'person',
    reason: 'CRM contact record 48213'
  })
};

fetch('https://{space}.{region}.api.niadra.com/v1/identity/assertions', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://{space}.{region}.api.niadra.com/v1/identity/assertions",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'handles' => [
        [
                'type' => 'phone_e164',
                'value' => '+14155550123'
        ],
        [
                'type' => 'system_id',
                'value' => '48213',
                'scope' => 'crm'
        ]
    ],
    'method' => 'system_import',
    'subject_kind' => 'person',
    'reason' => 'CRM contact record 48213'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json",
    "Idempotency-Key: <idempotency-key>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://{space}.{region}.api.niadra.com/v1/identity/assertions"

	payload := strings.NewReader("{\n  \"handles\": [\n    {\n      \"type\": \"phone_e164\",\n      \"value\": \"+14155550123\"\n    },\n    {\n      \"type\": \"system_id\",\n      \"value\": \"48213\",\n      \"scope\": \"crm\"\n    }\n  ],\n  \"method\": \"system_import\",\n  \"subject_kind\": \"person\",\n  \"reason\": \"CRM contact record 48213\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Idempotency-Key", "<idempotency-key>")
	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://{space}.{region}.api.niadra.com/v1/identity/assertions")
  .header("Idempotency-Key", "<idempotency-key>")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"handles\": [\n    {\n      \"type\": \"phone_e164\",\n      \"value\": \"+14155550123\"\n    },\n    {\n      \"type\": \"system_id\",\n      \"value\": \"48213\",\n      \"scope\": \"crm\"\n    }\n  ],\n  \"method\": \"system_import\",\n  \"subject_kind\": \"person\",\n  \"reason\": \"CRM contact record 48213\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://{space}.{region}.api.niadra.com/v1/identity/assertions")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Idempotency-Key"] = '<idempotency-key>'
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"handles\": [\n    {\n      \"type\": \"phone_e164\",\n      \"value\": \"+14155550123\"\n    },\n    {\n      \"type\": \"system_id\",\n      \"value\": \"48213\",\n      \"scope\": \"crm\"\n    }\n  ],\n  \"method\": \"system_import\",\n  \"subject_kind\": \"person\",\n  \"reason\": \"CRM contact record 48213\"\n}"

response = http.request(request)
puts response.read_body

{
  "op_id": "0192f7a1-5b10-7c3a-8e21-4d2f8a4c0e07",
  "status": "queued",
  "assertion_id": "0192f7a1-5b10-7c3a-8e21-4d2f8a4c0e06",
  "link_id": null
}

{
  "code": "<string>",
  "status": 123,
  "title": "<string>",
  "detail": "<string>",
  "request_id": "<string>",
  "type": "about:blank"
}