Hi @simon.brown,
I use the macOSUpgrade script in my environment. HCS has a great guide here: Upgrade to macOS Catalina using Self Service with Jamf Pro
You can send user's the initial alert that it is available via the app store here:

I'd also recommend "Include the policy in the Featured category" so it is easily visible when your Self Service is opened.
Jamf Pro 10.21 has recently added the ability to set a policy deferral duration (in days) relative to the first prompt a user receives.
This can be nicely paired with an alert to remind the User to update before a set deadline


I have previously used Nudge to alert users of updates. It may be the friendlier option to alert your Users.
Hi @shaquir that's really helpful - thank you! Been looking for something like Nudge for a long time.
No worries. It's a great solution.
Also, there is a #nudge group on MacAdmins Slack that stays pretty active with new updates and support.