Application not configured. Use Extensibility Test tenant in s/4 hana public cloud

 When you try to open Manage Logos app, in Starter system and Development tenant, it will not allow to create.

solution:

There are some limitations, you can only open this app in Development-Customizing tenant.

Reference Note: 3342103 - Key User Extensibility apps are not available or read only - SAP S/4HANA Cloud Public Edition