private String request() throws IOException {
    URL url = new URL("https://test.oppwa.com/v1/checkouts");

    HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
    conn.setRequestMethod("POST");
        conn.setRequestProperty("Authorization", "Bearer OGE4Mjk0MTc0ZTczNWQwYzAxNGU3OGNmMjY2YjE3OTR8cXl5ZkhDTjgzZQ==");
    conn.setDoInput(true);
    conn.setDoOutput(true);

    String data = ""
        + "entityId=8a8294174e735d0c014e78cf26461790"
        + "&amount=92.00"
        + "&currency=ZAR"
        + "&paymentType=DB";

    DataOutputStream wr = new DataOutputStream(conn.getOutputStream());
    wr.writeBytes(data);
    wr.flush();
    wr.close();
    int responseCode = conn.getResponseCode();
    InputStream is;

    if (responseCode >= 400) is = conn.getErrorStream();
    else is = conn.getInputStream();

    return IOUtils.toString(is);
}