//ButtonManager API
$ret = ch_post();
error_log($ret);
echo urldecode($ret);
function ch_post(){
    //API Credentials
    $accID = urlencode("accID");
    $username = urlencode("username_api1.website");
    $password = urlencode("password");
    $signature = urlencode("signature");
    $appID = urlencode("APP-ID");

    $endpoint = "https://api-3t.sandbox.paypal.com/nvp";
    $certpath = "C:certpath.pem";

    $ch_headers = array(
        "USER"=>$username,
        "PWD"=>$password,
        "SIGNATURE"=>$signature,
        "APPID"=>$appID,
        "VERSION"=>"51.0"
    );

    $ch_params = array(
        "METHOD"=>urlencode("BMCreateButton"),
        "OTHERPARAMS"=>urlencode("OTHER")
    );

    $ch = curl_init($endpoint);
    curl_setopt($ch,CURLOPT_HTTPHEADER,http_build_query($ch_headers));
    curl_setopt($ch,CURLOPT_CAINFO,$certpath);
    curl_setopt($ch,CURLOPT_POSTFIELDS,http_build_query($ch_params));
    curl_setopt($ch,CURLOPT_POST,TRUE);
    curl_setopt($ch,CURLOPT_HEADER,TRUE);
    curl_setopt($ch,CURLOPT_RETURNTRANSFER,TRUE);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
    curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, 2);
    curl_setopt($ch,CURLOPT_SSLVERSION, 6);
    $cexec = curl_exec($ch);
        if(!$cexec) {
            $response = "Failed: ".curl_error($ch)."(".curl_errno($ch).")";
            curl_close($ch);
            return $response;
        }
    curl_close($ch);
    return $cexec;
}