'git push heroku master' is still asking for authentication

Question

I have executed:

$ heroku login

But when I try to push, I\'m still asked for authentication:

$ git push heroku master
Usern         


        

Answer 1

It was possible to log in using Heroku API Key (Account Settings -> API Key) as mentioned by @andy mccullough, however, logging in was needed every time.

git fetch

resolved the issue in my case.