If you can't, ask your IT person to unblock access to: https://boom-cards.s3-us-west-2.amazonaws.com/
If your students' devices are not loading images, open this page in a browser on their device to confirm you can see the image. https://wow.BoomLearning.com/help/
If you can't, check your volume and mute settings.
See if your school has granted permission to import Microsoft classroom rosters. More info here