All applications can be retrieved via this API -
https://fusionauth.io/docs/v1/tech/apis/applications/#retrieve-an-application
The roles should be attached to the returned object under a roles array.
If you could provide some additional context around what you are attempting to accomplish, we may be able to provide additional feedback.
If you have a support contract, please file a ticket via your Zendesk or Slack channels for additional questions. Thanks!
Thanks,
Josh
FusionAuth