Required permission: Admin
A Google Workspace platform lets you set advanced settings which can’t be set from the admin console. For these settings an API call is used.
At first we mention GAM that is very popular among admins. It lets you to enter commands from a command line, eg. the following one will enable to establish the signatures of all employees in the company:
gam all users show signature
Similarly you can simply use the administrative rights to manage end users, without knowing their passwords - eg. setting the signatures, setting a delegated mailbox, redirect emails and other highly desirable operations. If you need more information, you can find it on the Help page for that product.
You can achieve everything that the GAM allows by using the appscript and automated activities of applications on Google Drive.