Unable to block the Change update in freshservice

We’re developing a custom app to prevent updates to the change properties and show a popup error when certain conditions are met. The notification part is working fine, but we’re having trouble preventing the update from going through. I’ve used event.helper.fail() to block the update, but it doesn’t seem to be working.

change popup error App.zip (5.2 KB)

@community-bot @Communiteq

Can anyone help to address this issue ?

Thanks,