Okta Auth in an iFrame

Hey does anyone know of a way to allow Okta to authenticate in an iFrame we placed in the community? 

Currently we have an iFrame pointing at a site that uses Okta to authenticate same as our community but won't display we are not sure if its a permissions thing on the community side or on the okta side. 

Has anyone had any experience with this. We are also open to other options of bringing another site into our community besides an iFrame.

Thanks.