Studio applications can only be configured by Studio administrators and by users assigned as application administrators for that application.
When a new application is created, only the application creator is assigned as an application administrator.
When configuring the application membership, most members should be application members only, able to view the application but not change its configuration. Only assign a user as an application administrator if they absolutely need to be able to configure the application.
Note that an application administrator does not need to be a Studio administrator (in other words, does not need to have the Administrator user role).
For details on configuring access to applications, see the Studio User's Guide.