Hi Yasin,
this is described in the previous section: "Standalone Apps"
https://docs.eu1.edge.siemens.cloud/apis_and_references/iectl/howtos/standalone-app.html
The tutorials are based on each other, i guess that's why it is missing in this section, but thanks for sharing this information.
i found that i have to run
iectl publisher workspace init
command. but this step is missing on the tutorial