Generate Ethereum Wallet using PHP

composer.json

{
    "require": {
        "sop/asn1": "^3.3",
        "sop/crypto-encoding": "^0.2.0",
        "sop/crypto-types": "^0.2.1",
        "kornrunner/keccak": "^1.0",
        "symfony/dotenv": "^4.0",
        "sc0vu/web3.php": "dev-master"
    }
}

GenerateEthereumWallet.php

<?php

require_once "vendor/autoload.php";

use Sop\CryptoTypes\Asymmetric\EC\ECPublicKey;
use Sop\CryptoTypes\Asymmetric\EC\ECPrivateKey;
use Sop\CryptoEncoding\PEM;
use kornrunner\keccak;

$config = [
    'private_key_type' => OPENSSL_KEYTYPE_EC,
    'curve_name' => 'secp256k1'
];

$res = openssl_pkey_new($config);

if (!$res) {
    echo 'ERROR: Fail to generate private key. -> ' . openssl_error_string();
    exit;
}

// Generate Private Key
openssl_pkey_export($res, $priv_key);

// Get The Public Key
$key_detail = openssl_pkey_get_details($res);
$pub_key = $key_detail["key"];

$priv_pem = PEM::fromString($priv_key);

// Convert to Elliptic Curve Private Key Format
$ec_priv_key = ECPrivateKey::fromPEM($priv_pem);

// Then convert it to ASN1 Structure
$ec_priv_seq = $ec_priv_key->toASN1();

// Private Key & Public Key in HEX
$priv_key_hex = bin2hex($ec_priv_seq->at(1)->asOctetString()->string());
$priv_key_len = strlen($priv_key_hex) / 2;
$pub_key_hex = bin2hex($ec_priv_seq->at(3)->asTagged()->asExplicit()->asBitString()->string());
$pub_key_len = strlen($pub_key_hex) / 2;

// Derive the Ethereum Address from public key
// Every EC public key will always start with 0x04,
// we need to remove the leading 0x04 in order to hash it correctly
$pub_key_hex_2 = substr($pub_key_hex, 2);
$pub_key_len_2 = strlen($pub_key_hex_2) / 2;

// Hash time
$hash = Keccak::hash(hex2bin($pub_key_hex_2), 256);

// Ethereum address has 20 bytes length. (40 hex characters long)
// We only need the last 20 bytes as Ethereum address
$wallet_address = '0x' . substr($hash, -40);
$wallet_private_key = '0x' . $priv_key_hex;

echo "\r\n   ETH Wallet Address: " . $wallet_address;
echo "\r\n   Private Key: " . $wallet_private_key;

I am getting this error :
PHP Fatal error: Uncaught Error: Class 'kornrunner\keccak' not found in /var/www/html/BS/index.php:50

I get the same I found this
https://gist.github.com/irmaster/099758d0266634fe7e830b5ab674b55b
it dose work