I just drop it here in case someone finds it useful:
If you use the Xiaomi Miio integration for your robot vacuum and you want to clean a zone you first need to determine the zone coordinates. The docs of the integration show how to get the coordinates using some android app or when using Valetudo firmware.
Since I do not use any of these, I needed to find a different way. And I found the solution at the iobroker-side. I took the code and put together a small command line tool which you can use to download the map of the vacuum from the cloud. You can then open it in the Xiaomi Vacuum Map Viewer to get the coordinates for your zones.
As I thought this could be useful for other HomeAssistant users I published my code incl. instructions on how to use it here: GitHub - da-mkay/mihome-vacuum-map-dl: Download rrmap of your vacuum from xiaomi cloud
PS: I know there is also lovelace-xiaomi-vacuum-map-card but for know I want to stick to the original Xiaomi Miio integration.