Setting up permissions is described in detail here: Permissions.
Permissions are set up globally in the Administrator window in the Universe tab in the Global access rights tab on the right.
In this tab, you can add user groups and assign them the necessary permissions, determining the group's role.
You can use a preset role or create your own. To create a new role, use the Roles button.
The Conditional column means that this permission clause would only be active if the user is Assigned to a task.
Global permissions would be inherited by all created projects. When creating a new project, you will be able to customize Global permissions by adding or deleting groups or users with certain roles.
Project permissions would be inherited by all project tasks. If necessary, you can customize permissions of a separate project task or task branch. To do so, go to the task's Properties (you can open this function by clicking the Properties button in the right part of the Cerebro window or via the task's context menu), click the Permissions button (the ‘key’ icon), uncheck ‘Include inheritable access rights’ and set up task permissions to suit your needs.