I have ruled out it is iphone/ipad/setting problems.
On android phone, there is notification sound.
I have thought of workaround e.g. sending email with gmail notification sound, but notifications sound is rather basic and simple. I dont understand why it is omitted.
AppSheet notifications on iOS use Apple’s push notification framework, which doesn’t currently support custom or audible sounds through AppSheet’s standard notification channel. The AppSheet mobile client for iOS only triggers a visual banner or lock-screen alert because the app doesn’t include the native iOS sound payload required for custom tones. Android behaves differently because its Firebase Cloud Messaging integration allows local sound playback when a notification arrives.
There’s no configuration in the AppSheet editor or app settings that overrides this behavior. If audible alerts are essential, the practical workaround is to pair a workflow or automation with an external notifier such as Gmail or a web service that sends an iOS push via a custom app. For production use, you can also submit a feature request through the AppSheet Feature Ideas board so the team can evaluate adding sound payload support to iOS notifications in a future release.