Unable to Login to Heroku via Cloud9

Hi,
I’m trying to Login to my Heroku via Cloud9 terminal to deploy a Rails App, but unable to do so due to some proxy problem. (See the screenshot below)
Can anybody help me with that ?

Thanks.

HTTP 410 is telling you the target resource is no longer available at the origin server and that this condition is likely to be permanent. It’s asking you if you are behind a proxy server, depends how your network is setup, most aren’t behind a proxy server. Did you signup on heroku?

Yes I already have heroku account,
I resolved the issue by installing the heroku gem and updating the heroku CLI