Is it possible to only use this home assistant with and iphone only ? do I have to create a local installation? Thnaks
No. You have to create local installation.
You welcome.
Generally, one wants to have HA running on something that’s powered and on 24/7.
Thanks! Is it possible to use a cloud base installation?
Yes people have done this but it is not supported or recommended.
The “local installation” device, that runs Home Assistant 24/7, can be something relatively inexpensive, such as a Raspberry Pi or an old laptop. Then you use your iPhone (or any browser) to access the system.