Minimalistic Creditas Bank API client

creditas.php

<?php

class Creditas {

    private $id;
    private $secret;

    public function __construct(string $id, string $secret)
    {
        $this->id = $id;
        $this->secret = $secret;
    }

    private function get(string $method, ?array $parameters = [])
    {
        $curl = curl_init();

        curl_setopt_array($curl, [
            CURLOPT_URL =>  'https://api.creditas.cz/oam/v1/'.$method,
            CURLOPT_POST => true,
            CURLOPT_POSTFIELDS => json_encode($parameters),
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => 30,
            CURLOPT_HTTPHEADER => [
                "Authorization: Bearer ".$this->secret,
                "Authorization-Bearer: ".$this->secret,
                "Content-Type: application/json",
                "Accept: application/json",
                "Pragma: no-cache",
                "Expires: -1",
                "Accept-Language: cs",
                "Cache-Control: no-cache,no-store,must-revalidate,max-age=-1,private"
            ]
        ]);

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

        curl_close($curl);

        if ($err) {
            echo "cURL Error #01: " . $err;
        } else {
            $response = json_decode($response, true);
            if ($response) return $response;

            if (array_key_exists("error", $response)) throw new \RuntimeException($response["error_description"]);

            throw new \RuntimeException("no response");
        }
    }

    public function account(string $id)
    {
        return $this->get('account/current/get', ['accountId' => $id]);
    }

    public function lastTransactions(string $id, int $num = 20): array
    {
        return $this->get('account/transaction/search', ['accountId' => $id, 'filter' => [], 'pageItemCount' => $num, "pageIndex" => 0]);
    }
}

$account = '...client id...';
$secret = '...your secret...';
$c = new Creditas($account, $secret);
//$c->account($account);
print_r($c->lastTransactions($account));