This app uses the wca-attendance-tracker Firebase project with a shared team passcode instead of accounts. One-time setup:

1. Authentication → Sign-in method → enable Anonymous.

2. Firestore → create doc worshipflow/config with field pin = your chosen passcode (string).

3. Firestore → Rules:

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /worshipflow/{doc} {
      allow read: if request.auth != null
        && doc != 'config';
      allow write: if request.auth != null
        && doc != 'config'
        && request.resource.data.pin ==
           get(/databases/$(database)/documents/worshipflow/config).data.pin;
    }
    match /worshipflow/sessions/{sub}/{planId} {
      allow read: if request.auth != null;
      allow write: if request.auth != null
        && request.resource.data.pin ==
           get(/databases/$(database)/documents/worshipflow/config).data.pin;
    }
    match /attendance/{userId} {
      allow read, write: if request.auth != null
        && request.auth.uid == userId;
    }
  }
}

4. Add the deployed domain under Authentication → Settings → Authorized domains.

To change the passcode later, edit worshipflow/config and tell the team the new code.