Below is a sample URL with the appropriate versioning and authorization code:

curl --request GET \ --url https://api.fonoa.com/Tax/v1/Calculations/521286e82bd84f5d8a50e5906a18918c \
  --header 'Accept: application/json' \
  --header 'Ocp-Apim-Subscription-Key: 8b144782eec54b159917c8c4a367d694'

const fetch = require('node-fetch');

let url = 'https://api-demo.fonoa.com/Tax/v1/Calculations/521286e82bd84f5d8a50e5906a18918c';

let options = {
  method: 'GET',
  headers: {
    Accept: 'application/json',
    'Ocp-Apim-Subscription-Key': '8b144782eec54b159917c8c4a367d694'
  }
};

fetch(url, options)
  .then(res => res.json())
  .then(json => console.log(json))
  .catch(err => console.error('error:' + err));

require 'uri'
require 'net/http'
require 'openssl'

url = URI("https://api-demo.fonoa.com/Tax/v1/Calculations/521286e82bd84f5d8a50e5906a18918c")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
http.verify_mode = OpenSSL::SSL::VERIFY_NONE

request = Net::HTTP::Get.new(url)
request["Accept"] = 'application/json'
request["Ocp-Apim-Subscription-Key"] = '8b144782eec54b159917c8c4a367d694'

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

fetch("https://api-demo.fonoa.com/Tax/v1/Calculations/521286e82bd84f5d8a50e5906a18918c", {
  "method": "GET",
  "headers": {
    "Accept": "application/json",
    "Ocp-Apim-Subscription-Key": "8b144782eec54b159917c8c4a367d694"
  }
})
.then(response => {
  console.log(response);
})
.catch(err => {
  console.error(err);
});

import requests

url = "https://api-demo.fonoa.com/Tax/v1/Calculations/521286e82bd84f5d8a50e5906a18918c"

headers = {
    "Accept": "application/json",
    "Ocp-Apim-Subscription-Key": "8b144782eec54b159917c8c4a367d694"
}

response = requests.request("GET", url, headers=headers)

print(response.text)