Hi Pawel,
You need to set specific permissions for your user and enable debugging in the xsengine.ini
The exact requirements are explained here:
"Debugging with SAP HANA Development Workbench"
https://help.hana.ondemand.com/help/frameset.htm?1beaa7aaadc743568c8144066d005dab.html
Best regards
Ercin Nurol
SAP Product Support