Transcript module Class 'Locale' error

In the Transcript module (4.1), when I view media uploaded as WebVTT, I get this error below. Any ideas? Thank you

 Error
Class 'Locale' not found

Details:

Error: Class 'Locale' not found in /var/www/html/modules/Transcript/src/Media/Renderer/Generic.php:36
Stack trace:
#0 /var/www/html/modules/Transcript/src/Media/Renderer/WebVTT.php(14): Transcript\Media\Renderer\Generic->prepareTextTracks()
#1 /var/www/html/application/src/View/Helper/Media.php(126): Transcript\Media\Renderer\WebVTT->render()
#2 /var/www/html/application/src/Api/Representation/MediaRepresentation.php(42): Omeka\View\Helper\Media->render()
#3 /var/www/html/application/view/omeka/admin/media/show.phtml(20): Omeka\Api\Representation\MediaRepresentation->render()
#4 /var/www/html/vendor/laminas/laminas-view/src/Renderer/PhpRenderer.php(519): include('/var/www/html/a...')
#5 /var/www/html/vendor/laminas/laminas-view/src/View.php(194): Laminas\View\Renderer\PhpRenderer->render()
#6 /var/www/html/vendor/laminas/laminas-view/src/View.php(222): Laminas\View\View->render()
#7 /var/www/html/vendor/laminas/laminas-view/src/View.php(187): Laminas\View\View->renderChildren()
#8 /var/www/html/vendor/laminas/laminas-mvc/src/View/Http/DefaultRenderingStrategy.php(98): Laminas\View\View->render()
#9 /var/www/html/vendor/laminas/laminas-eventmanager/src/EventManager.php(319): Laminas\Mvc\View\Http\DefaultRenderingStrategy->render()
#10 /var/www/html/vendor/laminas/laminas-eventmanager/src/EventManager.php(171): Laminas\EventManager\EventManager->triggerListeners()
#11 /var/www/html/vendor/laminas/laminas-mvc/src/Application.php(360): Laminas\EventManager\EventManager->triggerEvent()
#12 /var/www/html/vendor/laminas/laminas-mvc/src/Application.php(341): Laminas\Mvc\Application->completeRequest()
#13 /var/www/html/index.php(21): Laminas\Mvc\Application->run()
#14 {main}