Using Google Home (assistant) speaker for notifications/alarms?

You might try starting here Door Sensor + Google Home + IFTTT. There are some updates since this post such as variables so read through that thread. I haven’t messed with it in awhile but just ask if you have any questions.

I seem to recall other discussions/options using GH for announcements but don’t recall exactly where. If native notifications discussed above become a reality, then all of this changes.