Many OAuth2 providers such as Outlook and Yahoo do not support redirect URIs of form 'fb(clientId)://authorize/' or 'com.myapp.name:/oauth2Callback' because they are not valid URLs. However, they do support URIs of forms 'urn:ietf:wg:oauth:2.0:oob' or 'https://mydomain.com/oauth2callback'. The OAuth2 library should similarly support these until such time that more providers support app bundle names as part of the redirect URI.