We need to go deeper.
Google has released an update to the Assistant app for iOS, in which it added support for Teams for Siri. Now you can call an assistant at any time, although with the help of a rather strange construction – “Hi, Siri, Okay, Google.”
In order for the function to work, you need to have the “Commands” application on the iPhone and install a new “shortcut” for the “Assistant” in it. By default, Google offers the phrase “Okay, Google”, but it can be replaced with a shorter one.
After that, the assistant can be called by saying the installed command after “Hi, Siri”. However, due to the fact that this is a third-party application, and not part of the system, Assistant requires unlocking the iPhone for use. And before you ask anything, you have to wait until the application starts.