Getting this error while doing unit test for external API

class TestApi(common.TransactionCase):
    def setUp(self):
        super(TestApi, self).setUp()
        self.password = "admin1"
        self.user = new_test_user(self.env, login="admin1", password=self.password)


    def test_check_associate(self):
        params = {
            "db": self.env.cr.dbname,
            "login": self.user.login,
            "password": self.password,
        }
        url = "http://{}:{}{}".format(HOST, PORT, "/api/auth/token")
        response = self.opener.post(url, json=params)
        self.assertEqual(response.status_code, 200)
        self.assertEqual(response.headers["Content-Type"], "application/json")
        data = response.json()
        session = root.session_store.get(data["session"]["sid"])
        self.assertEqual(session.login, 'admin')