curl --request POST \
  --url https://api.filexpress.app/api/external/cash-registers/open \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "branch_id": "3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01",
  "user_id": "3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01",
  "opening_amount": 100,
  "notes": "Turno mañana"
}
'

const options = {
  method: 'POST',
  headers: {'X-API-Key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    branch_id: '3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01',
    user_id: '3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01',
    opening_amount: 100,
    notes: 'Turno mañana'
  })
};

fetch('https://api.filexpress.app/api/external/cash-registers/open', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://api.filexpress.app/api/external/cash-registers/open"

payload = {
    "branch_id": "3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01",
    "user_id": "3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01",
    "opening_amount": 100,
    "notes": "Turno mañana"
}
headers = {
    "X-API-Key": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.filexpress.app/api/external/cash-registers/open",
  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([
    'branch_id' => '3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01',
    'user_id' => '3b8e2f10-7c4d-4a9e-b1f2-5d6c7e8f9a01',
    'opening_amount' => 100,
    'notes' => 'Turno mañana'
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-API-Key: <api-key>"
  ],
]);

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

curl_close($curl);

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