Solution found by user abqnm666 on reddit.
"In the Ring camera skill, turn off the notifications for Motion alerts, but don’t disable the skill. Next, go to Routines in the left side menu of the Alexa app.
Create a routine by tapping Devices and then (name of Ring device), then “Motion” as the trigger, and for the action, choose Messaging > Announcement, and tell it what you want Alexa to say. You can be creative or just have it say the same things as the notification in the skill does, like “there is motion in the garden.”
Then choose which Echo devices to alert on.
Then set the times/days you want it to alert during, and if you want it to suppress repeat notifications for any period of time. Save the routine and you’ve got a schedule for notifications."