Question about Gardena washing brush

Buy the matching stem and then the hose connection with a normal coupling. Water feature 90. art. No. 5552-20

Without a handle, the water hose can be mounted with a normal coupling. However, the brush then wobbles back and forth, i.e. it is not fixed.
The matching coupling is attached to the original handle. (Gardena plug-in coupling with thread)

Thank you for the answer. So with normal components. Handle and adapter. I was confused about the high-pressure cleaner...