Does a cross-domain iframe read the hub's push subscription?

landing origin: · UA:

⚠️ iOS / iPadOS (WebKit) detected. Web Push on iOS works only inside a home-screen-installed web app, never in a Safari tab, and a cross-site iframe cannot subscribe at all. The popup/iframe flow below cannot complete here — see the README's Android/iOS section for why the external-domain technique is not viable on iOS.
  1. In each section: click Subscribe, click Allow in the popup, close it.
  2. Click Re-check iframe. Compare the ✅/❌ verdicts.