Connect to Messenger
1 · Give this server a public HTTPS address — cloudflared tunnel --url http://localhost:8000
2 · Meta dashboard → Messenger → callback URL https://YOUR-DOMAIN/webhook + the verify token above
3 · Subscribe to messages, messaging_postbacks, message_echoes, messaging_referrals
— message_echoes lets the bot step aside when you reply by hand; messaging_referrals is what tells it which ad a customer came from
4 · Go live: request pages_messaging via App Review, switch the app to Live mode