Bluebubbles Server Manual Firebase Setup Rule Is Insecure #783

In the manual Firebase setup instructions here step 4 states: Set the rule's condition from allow read, write: if false; to allow read, write: if true; (Change false to true) and click Publish.

This results in the following rule

rules_version = '2';

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if true;
    }
  }
}

However upon saving this rule I see the following error:

Your security rules are defined as public, so anyone can steal, modify, or delete data in your database

There has to be a more secure way to set this up so that Firebase isn't open to anyone right? I tried to change the setting to allow read, write: if request.auth != null; but was unable to receive cloudflare URL updates with that setting.