In Spaceti, both Managers and Admins can change user roles between User and Manager roles. This can be easily done through the web interface.
The Admin role cannot be changed via the dashboard and can only be modified with the assistance of Spaceti support.
At the homepage, go to the "Users" tab.
Select the user whose role you want to change, and click on "Details" using the three dots ••• on a right side.
See the popup window with a user account. And then, in the dropdown menu, change the user's role to the desired role.