<?php
$consumerKey = '3nVuSoBZnx6U4vzUxf5w';
$consumerSecret = 'Bcs59EFbbsdF6Sl9Ng71smgStWEGwXXKSjYvPVt7qys';
$accessToken = 'token';
$accessTokenSecret = 'secret';

$url = 'https://api.x.com/1.1/search/tweets.json';
$query = 'nasa';
$resultType = 'popular';

function createAuthHeader($url, $params, $consumerSecret, $accessTokenSecret) {
    ksort($params);
    $baseString = 'GET&' . rawurlencode($url) . '&' . rawurlencode(http_build_query($params, '', '&'));
    $signingKey = rawurlencode($consumerSecret) . '&' . rawurlencode($accessTokenSecret);
    $params['oauth_signature'] = base64_encode(hash_hmac('sha1', $baseString, $signingKey, true));
    return 'Authorization: OAuth ' . urldecode(http_build_query($params, '', ', '));
}

$oauthParams = [
    'oauth_consumer_key' => $consumerKey,
    'oauth_nonce' => md5(uniqid(rand(), true)),
    'oauth_signature_method' => 'HMAC-SHA1',
    'oauth_timestamp' => time(),
    'oauth_token' => $accessToken,
    'oauth_version' => '1.0',
    'q' => $query,
    'result_type' => $resultType
];

$authHeader = createAuthHeader($url, $oauthParams, $consumerSecret, $accessTokenSecret);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url . '?q=' . urlencode($query) . '&result_type=' . $resultType);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_HTTPHEADER, [$authHeader]);

$result = curl_exec($ch);
curl_close($ch);
print_r($result);