Encountering error "Request has invalid Client token" but my credentials is correct

Question

I'm having this error when I call the startDocumentTextDetection even I have the correct credentials because I was able to upload the my pdf in s3. I also allowed Textract to call other services on my behalf.

$client = new TextractClient([
            'region' => env('AWS_DEFAULT_REGION'),
            'version' => '2018-06-27',
            'credentials' => [
                'key'    => env('AWS_ACCESS_KEY_ID'),
                'secret' => env('AWS_SECRET_ACCESS_KEY')
            ]
        ]);

$result = $client->startDocumentTextDetection([
            'ClientRequestToken' => 'DocumentDetectionToken',
            'DocumentLocation' => [ // REQUIRED
                'S3Object' => [
                    'Bucket' => 'XXXXX',
                    'Name' => 'HNlLrVxE4cDqyJh0RHmSfTGtZVKzOWUG75ycHfyE.pdf',
                ],
            ],
            'FeatureTypes' => ['FORMS','TABLES'],
            'JobTag' => 'HNlLrVxE4cDqyJh0RHmSfTGtZVKzOWUG75ycHfyE.pdf',
            'NotificationChannel' => [
                'RoleArn' => 'XXXXX', // REQUIRED
                'SNSTopicArn' => 'XXXXX', // REQUIRED
            ],
            'OutputConfig' => [
                'S3Bucket' => 'XXXXXX',
            ],
        ]);