'git push heroku master' is still asking for authentication

I got around this by logging in with the following :

username : email used to register to heroku (Also been able to leave this field blank)

password : heroku auth token (API Key)

where the auth token can be retrieved by $ heroku auth:token or via the Account Settings in Heroku

First find the _netrc file that is created by heroku. In windows it can be found in C:\Users\User Name\_netrc.

That file contains credentials for git.heroku.com

machine git.heroku.com
     login [email protected]
     password xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx

Use that login and password when ask for authentication after $ git push heroku master command

I had the same problem (git couldn't authenticate). It happend that GIT wants to read auth data from %HOME%/_netrc file and on Windows you don't have this variable (only %USERPROFILE% and %HOMEDRIVE% + %HOMEPATH%)

i set HOME to %USERPROFILE% (the place where heroku saved _netrc file) and GIT started working