Can't login

[dgleba]

EDIT:
I had some mistakes below. I edited it.

---

I created superuser admin with password top_secret.

I then did

curl -X POST -d '{"username": "admin","password": "top_secret"}' -H 'Content-Type: application/json'  http://192.168.88.60:6461/api/auth/token/login/

I get: {"non_field_errors":["Unable to log in with provided credentials."]}

I tried to login to: http://192.168.88.60:6461/admin/login/?next=/admin/

at: http://192.168.88.60:6461/api/auth/token/login -- I get

"non_field_errors": [
        "Unable to log in with provided credentials."
    ]

Any ideas what's wrong?