How to start with a private project template on github

I tried to build a ionic3 app in teamcity using command line and i ran into a login problem. I am asked to enter my github account and password manually in the auto-building process.
Is there any solution to login into my github account automatically in command?
Is there any parameters for login info when i am using private project on github as a template? like “ionic start myConferenceApp https://github.com/ionic-team/ionic-conference-app -e myEmail -p myPassword” ?
so it can use private template automatically and build in the following steps.
Could anyone give me some suggestions pls. Thanks.

The “ionic start myPrivateApp https://github.com/xxx” command does not work automatically in bat file. It requests for github account. However it works in Teamcity command line using"echo y|ionic start myPrivateApp https://github.com/xxx" without a request for github account info.