<?php
// set API Endpoint and API key 
$endpoint = '/v1/minimum-viable-authentications';
$access_key = 'API_KEY';

// Initialize CURL:
$ch = curl_init('https://api.nickel.eu/customer-authentication-api-v2'.$endpoint.'?access_key='.$access_key.'');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

// Store the data:
$json = curl_exec($ch);
curl_close($ch);

// Decode JSON response:
$exchangeRates = json_decode($json, true);

// Access the exchange rate values, e.g. GBP:
echo $exchangeRates['rates']['GBP'];