Attaching Cookie from in App Browser to application calls

We are implementing social auth with instagram as well as facebook, and likely more in the near future. We utilized the facebook plugin for native and it works great, however IG does not appear to be supported natively in V4 and we did our own auth service through our backend servers and an in app browser, however we are unable to attach the cookie from the auth request to the application so subsequent calls to the server after are not authenticated.

Does anyone have any suggestions of a better way to do this or a way to get the cookie?