When set, this property disables app verification for the purpose of testing phone authentication. For this property to take effect, it needs to be set before rendering a reCAPTCHA app verifier. When this is disabled, a mock reCAPTCHA is rendered instead. This is useful for manual testing during development or for automated integration tests.
In order to use this feature, you will need to whitelist your phone number via the Firebase Console.
The default value is false (app verification is enabled).