Hi joy3410,
We see that you're looking for an Auto-Reply Message for Focus other than Driving, and we'd like to do what we can to help.
The article viewed before posting, Use the Driving Focus on your iPhone to concentrate on the road, does have the Auto-Reply Message feature, along with the Focus Status.
However, the other Focus options also give the option to "turn on Share Focus Status so that apps display to people who message you that you have notifications silenced." This can be helpful to let others know you have notifications silenced. Read more about that here:
Use Focus on your iPhone, iPad, or iPod touch
You can also submit feedback about the Auto-Reply Message for other Focus statuses here: Product Feedback
Select iPhone to get started.
Take care!