When developing and creating your own sheet and publish them as Community Sheet, you might want at some point to have them as Base Sheet.
This was not possible out of the box in the product before but since Qlik Sense June 2018 this feature has been implemented.
Basically you can open the application in the Qlik Sense Hub, right click on the Community Sheet you want to publish and press Approve
You also have the possibility to un-promote base sheet and move them in the Community Sheet section
What's new in Qlik Sense June 2018?
What's new Qlik Sense May 2021?
Environment:
Qlik Sense Enterprise on Windows , June 2018 and newer
See Security Rule Requirements for Promoting Community Sheets for more details on the implementation of this functionality.