Specify how the app check provider should be configured. The new configuration is
in effect when this call returns. You must call getToken()
after this call to get a token using the new configuration.
This custom provider allows for delayed configuration and re-configuration on all platforms
so AppCheck has the same experience across all platforms, with the only difference being the native
providers you choose to use on each platform.
Returns an AppCheck token.
An App Check provider. This can be either the built-in reCAPTCHA provider or a custom provider. For more on custom providers, see https://firebase.google.com/docs/app-check/web-custom-provider