Since my update it is no longer possible to print receipt as raw print.
In erpnext v13-beta9 this was possible.
How can I get back this behavior?
If you click on Print Receipt in POS there is opening the preview with the selected print-format but not in raw printing.
I set my custom print format as default for POS invoice and its activated as raw print.
Is it a bug or a feature? 
Or is there elsewhere a possibility to activate raw printing for POS and POS Invoice I have not found?
For now it is only possible to open the paid invoice via pos-invoice or Open Form View to print with POS-Printer.