No, no, no, no 10.0.0.15 was mine IP that I used in the demo. You should replace this with an IP from your subnet. For example if your router interface is accessible on 192.168.0.1 and the clients connected to it are in this range 192.168.0.2-255 you should replace 10.0.0.15 with 192.168.0.15 (if there is no such client in your network already). I should make this section more clear in the article. Thank you for making me notice that. And the config folder is located in /mnt/data/supervisor/homeassistant in the VM, but you better use the File editor or Samba add-ons from the add-on store.