Single Sign-On is not working for Visual flow skill

Summary:

Hi Experts,

We have created a Visual flow custom skill and associated to Digital Assistant. The necessary config has been made at Visual flow skill state and settings level In order to enable Single Sign On option. So that BOT will provide response without asking for sign-on when user queries any utterance related to visual flow skill . But its not working as expected. Always force the user to click on sign-on token when user try to ask any question from Oracle.

We are not sure what other option needs to be enabled to skip the user authentication. Your input and suggestion will help us to resolve the issue.