Get Authorization Code for exchange with Oauth server

[newtonnthiga]

Is it possible to get back an authorization code that I can then exchange with my custom Oauth server for access token, id token and refresh token? I need this for my custom auth backend but still want to use native MSAL on mobile for the login UX

As far as I can tell AuthenticationResult only returns

final class AuthenticationResult {
  /// The access token requested.
  final String accessToken;

  /// Gets the authentication scheme (Bearer, PoP, etc)....
  final String authenticationScheme;

  /// The expiration time of the access token returned in the Token property.
  /// This value is calculated based on current UTC time measured locally and
  /// the value expiresIn returned from the service.
  /// Please note that if the authentication scheme is 'pop',
  /// this value reflects the expiry of the 'inner' token returned by AAD and
  /// does not indicate the expiry of the signed pop JWT ('outer' token).
  final DateTime expiresOn;

  /// Gets the JWT format id_token. This value conforms to "RFC-7519" and
  /// is further specified according to "OpenID Connect Core".
  /// Note: MSAL does not validate the JWT token.
  final String? idToken;

  /// Authority used in creating the app.
  final String authority;

  /// A unique tenant identifier that was used in token acquisition.
  /// Could be null if tenant information is not returned by the service.
  final String? tenantId;

  /// The scopes returned from the service.
  final List<String> scopes;

  /// Gets the correlation id used during the acquire token request.
  /// Could be null if an error occurs when parsing from String or if not set.
  final String? correlationId;

  /// Microsoft account details.
  final Account account;
}