Use the PHP SDK

composer require leadpingai/sdk

<?php

require __DIR__ . '/vendor/autoload.php';

use Http\Promise\FulfilledPromise;
use Http\Promise\Promise;
use Leadping\OpenApiClient\LeadpingOpenApiClient;
use Microsoft\Kiota\Abstractions\Authentication\AuthenticationProvider;
use Microsoft\Kiota\Abstractions\RequestInformation;
use Microsoft\Kiota\Http\GuzzleRequestAdapter;

final class LeadpingAuthenticationProvider implements AuthenticationProvider
{
    public function __construct(private readonly string $credential) {}

    public function authenticateRequest(
        RequestInformation $request,
        array $additionalAuthenticationContext = []
    ): Promise {
        $uri = parse_url($request->getUri());
        if ($uri === false ||
            strtolower($uri['scheme'] ?? '') !== 'https' ||
            strtolower($uri['host'] ?? '') !== 'api.leadping.ai') {
            throw new RuntimeException('Refusing to send a credential to this destination.');
        }
        $request->getHeaders()->tryAdd('Authorization', 'Bearer ' . $this->credential);
        return new FulfilledPromise($request);
    }
}

$credential = getenv('LEADPING_API_KEY');
if ($credential === false || $credential === '') {
    throw new RuntimeException('LEADPING_API_KEY is not set.');
}

$adapter = new GuzzleRequestAdapter(new LeadpingAuthenticationProvider($credential));
$client = new LeadpingOpenApiClient($adapter);
$lead = $client->leads()->byId('lead-id')->get()->wait();
if ($lead === null) {
    throw new RuntimeException('Leadping returned no lead.');
}
echo $lead->getId(), PHP_EOL;

$source = $client->sources()->byId("source-id")->get()->wait();