I am using team managed Jira Board for zephyr scale > But I am not able to see Test button/label in top menu on dash board to create test case I need to select zephyr scale separately & create test...
As far as I'm aware there is no Test button/label on a dashboard that will allow you to create or import test cases. To import test cases you need to be in the Zephyr Scale app. Once inside you can create test cases individually (1), in bulk (2), or by import (3).
If you're unable to see these options it might be a security setting. Security settings can be found in Project Settings > Apps > Zephyr Scale...
In this example the permission system is disabled. In your project it might be enabled and your user/role/group is not included in the relevant permission attribute.
If neither of these suggestions help, I would contact SmartBear Support