Unable to log in with the authentication information provided

[labike]

when i post data, i always get this msg: Unable to log in with the authentication information provided

class CustomBackend(ModelBackend):
    def authenticate(self, username=None, password=None, **kwargs):
        try:
            user = User.objects.get(Q(username=username)|Q(mobile=username))
            if user.check_password(password):
                return user
        except Exception as e:
            return None

i'm follow offical website config, but don't know why not post data to API?