We recently built a Custom app for internal employees and distributed it using redemption codes from Apple Business Manager. I pushed an app update that is approved and users with new redemption codes are able to download the new version. How do existing users with the old version get the new version update? So far the apps on phones have had no push notification asking to update or no automatic updates have happened. It will be very inconvenient to send new redemption codes every time there is a bug fix or update. How is this handled?
The updates are handled automatically. Once the new app version is approved on App Store, it seems to take 3-4 days for the apps already installed on users' phones to automatically receive the update.