Add secure AGOL dashboard app to Portal with stored credentials?

[kmsmikrud]

Hi,

I had posted last week and I'm still trying to figure out how to share an AGOL Dashboard to our Portal. The AGOL dashboard is secure. I am trying to Add Item -> Add an application but the option to store credentials similar is not an option. 

Is it possible to store credentials for a web app? I'm trying to figure out if we are missed a setting our Portal (version 10.8.1).

Thanks,

Kathy