User wants to grant permissions to an employee to be able to add clients in Core. How to do that?
To be able to access any screen or feature in Core, you need to have the right security permissions and also the right subscription package assigned to you. In this particular instance, you need to have a Manager subscription package; something like Time & Expense subscription will not allow you to access the Clients screen at all. On top of that, you need the right security permissions to be able to see and edit data.
You can use the Manage Subscriptions screen to buy subscriptions and assign them to the relevant users. This information is permission-driven and only available to Core account owners and admin users. Check the Core Help for details.