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 -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” 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" without a request for github account info.