When running the Kiosk app, iPads will be constantly reaching out to the server every five minutes to check if there have been any updates.
Every time an iPad prompts the server, it will look for any changes that have been made to its experience, theme, or badge, while also receiving new cached information (invites, hosts, etc)
So as soon as an administrator has saved an update to anything linked to that device, there is nothing else that needs to be done.
The iPad will be up to date within five minutes.
However, if you want to see the updated changes right away, you can do so from the Kiosk Experience's Welcome page:
On the Kiosk app, tap the 'i' icon in the top-right corner of the Welcome Page.
Tap Refresh Theme.
Note: If your device loses internet connection, it will no longer be able to call the server for updates. To learn how to set up offline notifications, check out This Article.