I have tried for well over a year to get Ring to do one of the following.

1. Allow me to schedule when alerts are enabled in the Alexa Ring skill
2. Use my iOS Ring app motion monitoring settings and alert schedules to
   prevent motion alerts from being sent to Alexa (if that is how it works).
   I assume they are pushed to Alexa by Ring servers but it could be the
   Alexa skill has a way of getting them itself (I doubt it very much).

Right now and for as long as I have known, my app settings provide no
control over Alexa announced motion alerts.
Every spring we have lots of large moths that are apparently attracted by
the doorbell light or otherwise fly in and around the doorbell and trigger motion.
And we can have birds flying in a large portion of the year.

I want Alexa motion alerts during the day but do not want them waking me at night.
It does not matter whether I turn motion off in the app or set an OFF schedule.
I get Alexa notifications unless I go into the Alexa Ring skill each night and manually
turn them off and then remember to turn them back on the next morning.

I cannot even speak intelligently about this with customer service.
EVERY ONE OF THEM, winds up telling me to call Amazon even though I
lead them thoroughly through the fact that RING provides the Alexa Ring skill, NOT AMAZON.
TODAY I told them that since Amazon now owns Ring, they need to call each other and make this stuff work adequately. Of course, they shook in their boots.

Just Google for Alexa Skill Kit for confirmation of who provides what.