Replace your existing Worker code with the new version (notion-proxy-worker.js). It now handles GET, POST and DELETE so Spendly can read from and write to Notion.
Step 06 — iPhone
Add to Home Screen
Safari → Share → "Add to Home Screen".
Step 07 — Automation
iOS Shortcuts for Apple Pay
Shortcuts app → Automation → + → Apple Pay → Payment completed → Open URL → paste this app's URL.