Hi @coxuzi
We made some changes for this credit slip functionality in QloApps Version 1.4.0 but the flow was not completed. We are still working on this and it is still in development phase.
The whole flow will be completed in the next version 1.5.0 which will be released soon.
So please wait for the release of the next version.

Hi @gero
This is not a default feature of QloApps. So we cannot do it by configuring the backend of the system.
The requirement can be achieved by customizing the system.
So please raise a ticket so that we can discuss it through.
https://webkul.uvdesk.com/en/customer/create-ticket/