Are these url s correct? $baseUrl = "na3.docusign.net/restapi";

$consentUrl = "https://account.docusign.com/oauth/auth?response_type=code&scope=$scope&client_id=$clientId&redirect_uri=$redirectUri";

the JWT headers

$payload = =

        'iss' => $clientId,

        'sub' => $apiUserId,

        'aud' => 'account.docusign.com',

        'scope' => 'signature impersonation',

        'iat' => $now,

        'exp' => $now + 3600 // 1 hour expiration

    ];

$tokenUrl = "https://account.docusign.com/oauth/token";

$config=$apiClient->getConfig();

    $config->setHost('https://na3.docusign.net/restapi');