Android OAuth Trouble

Hi everyone, I'm trying to use the new OAuth2 support for an Android app. I'm running into issues with the redirect URL field. I've read the help article here: https://www.bungie.net/7_Developers-Bungienet-Authentication/en/Help/Article/45481, which says, ". If you are creating a mobile app, the Redirect URL may use a scheme that uniquely identifies your application which will be launched by the platform." However, I haven't been able to save a redirect url that doesn't start with https I haven't ever written anything using OAuth before, so it's possible I'm missing something. Any help would be appreciated!