To manage administrative privileges, simply head over to the Configuration tab and click on Roles.
Then, choose the relevant employee, click on "Assign roles," and select "Administrator."
The second way is tab Configuration → People → Choose an employee → Administration → Roles → Edit → Save:
If you haven't yet added a user profile you'd like to assign administrator privileges to, check out the article on adding new users.
At Calamari, the number of Administrators is unlimited.