Removing public repository on GitHub

I am a co-founder of Pawmaw.com

Someone just publicly of posted on public repository

https://github.com/itdev-1210/pawmaw/blob/37e674fed7c8a712fadb9c93dc19db97d8e10966/.env.example

How can I remove it? 

Or make it private  I am not in contact with him anymore 

Thanks 

I think you would want to contact https://support.github.com/contact/dmca-takedown if someone has posted your property in a public repo.