Use the following code to get all licenses assigned to specific WooCommerce order:
use \IdeoLogix\DigitalLicenseManager\Database\Repositories\Licenses;
$licenses = Licenses::instance()->get(['order_id' => 358]);
foreach($licenses as $license) {
echo $license->getId() . "\n";
echo $license->getDecryptedLicenseKey() . "\n";
echo $license->isExpired() . "\n";
}