Convert Dynamic HTML Resources to a PDF File using REST API

Error: 400 - Array ( [cpf:status] => Array ( [completed] => 1 [type] => Invalid papi Engine [title] => Invalid engines input for papi request [status] => 400 [report] => {"error_code":"INVALID_REQUEST"} ) )
hii i am using Convert HTML Resources to a PDF File which is not working.kindly help to resolve this issue 

<?php

// Function to get an access token from Adobe API
function getAccessToken($clientId, $clientSecret) {
$url = 'https://ims-na1.adobelogin.com/ims/token/v3';
$data = [
'grant_type' => 'client_credentials',
'client_id' => $clientId,
'client_secret' => $clientSecret,
'scope' => 'openid'
];

$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));

$response = curl_exec($ch);
curl_close($ch);

$responseData = json_decode($response, true);
return $responseData['access_token'] ?? null;
}

// Function to convert HTML to PDF using Adobe's API
function convertHtmlToPdf($accessToken, $apiKey) {
$url = 'https://cpf-ue1.adobe.io/ops/:create';

// Prepare the HTML content
$htmlContent = '';

// Create a temporary file for the HTML content
$tempHtmlFile = tempnam(sys_get_temp_dir(), 'html_') . '.html';
file_put_contents($tempHtmlFile, $htmlContent);

// Create a ZIP file with the HTML
$zipFilePath = tempnam(sys_get_temp_dir(), 'html_to_pdf_') . '.zip';
$zip = new ZipArchive();
if ($zip->open($zipFilePath, ZipArchive::CREATE) === TRUE) {
$zip->addFile($tempHtmlFile, 'input.html');
$zip->close();
} else {
echo "Failed to create ZIP file.";
return;
}

// Prepare the payload as a JSON string
$payload = json_encode([
'contentAnalyzerRequests' => [
[
'cpf:engine' => [
'repo:assetId' => 'InputFile0', // Use placeholder for input file
],
'cpf:inputs' => [
'documentIn' => [
'cpf:location' => 'InputFile0', // Input file name
'dc:format' => 'application/zip', // Input format
],
'params' => [
'cpf:inline' => [
'print' => [
'includeHeaderFooter' => true,
],
'pageLayout' => [
'pageHeight' => 8.5,
'pageWidth' => 11,
],
],
],
],
'cpf:outputs' => [
'documentOut' => [
'cpf:location' => 'multipartLabelOut',
'dc:format' => 'application/pdf',
],
],
],
],
]);

// Prepare the cURL request
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
"Authorization: Bearer $accessToken",
"x-api-key: $apiKey",
]);

// Use CURLFile to add the ZIP file and the JSON payload
$postFields = [
'InputFile0' => new CURLFile($zipFilePath),
'contentAnalyzerRequests' => $payload // Pass the JSON payload as a string
];

curl_setopt($ch, CURLOPT_POSTFIELDS, $postFields);

// Execute the request
$response = curl_exec($ch);
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

if ($httpCode === 200) {
// Check if the response is PDF data
if (strpos($response, '%PDF-') === 0) {
// Save PDF to the specified directory
$outputPdfPath = 'F:/xampp/htdocs/pdf/output.pdf';
file_put_contents($outputPdfPath, $response);
echo "PDF generated successfully. <a href='pdf/output.pdf'>Download PDF</a>";
} else {
echo "Error: Unexpected response format.";
}
} else {
// Handle the error response
$errorDetails = json_decode($response, true);
echo "Error: " . $httpCode . " - " . print_r($errorDetails, true);
}

// Clean up temporary files
unlink($tempHtmlFile);
unlink($zipFilePath);
}

// Your Adobe API credentials
$clientId = 'id value'; // Replace with your Client ID
$clientSecret = 'secret'; // Replace with your Client Secret
$apiKey = 'api key'; // Replace with your API Key

// Get access token
$accessToken = getAccessToken($clientId, $clientSecret);
if ($accessToken) {
// Convert HTML to PDF
convertHtmlToPdf($accessToken, $apiKey);
} else {
echo "Failed to generate access token.";
}
?>