curl --request GET \
  --url https://api.tilta.io/v1/contacts/{external_id} \
  --header 'Authorization: Bearer <token>'

const options = {method: 'GET', headers: {Authorization: 'Bearer <token>'}};

fetch('https://api.tilta.io/v1/contacts/{external_id}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://api.tilta.io/v1/contacts/{external_id}"

headers = {"Authorization": "Bearer <token>"}

response = requests.get(url, headers=headers)

print(response.text)

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.tilta.io/v1/contacts/{external_id}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>"
  ],
]);

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

curl_close($curl);

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

{
  "external_id": "<string>",
  "buyer_external_id": "<string>",
  "assign_to_all_invoices": true,
  "created_at": 1582896122,
  "updated_at": 1582896122,
  "salutation": "MR",
  "first_name": "<string>",
  "last_name": "<string>",
  "email": "jsmith@example.com",
  "phone": "+491711010101",
  "address": {
    "postcode": "12345",
    "city": "Berlin",
    "country": "AF",
    "street": "Example Street",
    "house": "42b",
    "additional": "c/o Testimonial"
  }
}

{
  "code": "BAD_REQUEST",
  "error": "Request validation failed. 1 issue found.",
  "issues": [
    {
      "code": "INVALID_TYPE",
      "path": "body.registered_at",
      "message": "Invalid type"
    }
  ]
}

{
  "error": "Unauthorized",
  "code": "UNAUTHORIZED"
}