Oi Otávio, eu já fiz isso, eu tentei agora...
Como eu também ja tentei
$ docker login -u "user" -p "pass" docker.io
$ docker login
Authenticating with existing credentials...
Login Succeeded
$ docker push herbertmauadie/node2
The push refers to repository [docker.io/herbertmauadie/node2]
7f24a5f7f97b: Preparing
6aec204a3c55: Preparing
dbb11aa387dc: Preparing
05708835b45e: Preparing
aaaede926ce1: Preparing
6bb414a5ce23: Preparing
f2c194ac8a61: Preparing
2a50ea4f9e8e: Preparing
634249d50b9e: Preparing
68e35493907b: Preparing
e84b9d651af1: Preparing
634249d50b9e: Waiting
6bb414a5ce23: Waiting
68e35493907b: Waiting
f2c194ac8a61: Waiting
2a50ea4f9e8e: Waiting
e84b9d651af1: Waiting
denied: requested access to the resource is denied
herbe@DESKTOP-IQVFKKH MINGW64 ~/Desktop/Aws (master)