Sleepr App

Sleepr brings back to life the missing sleep timer feature of macOS, removed from Ventura.
It provides a quick access to set a timer at the end of which your Mac goes into sleep mode.
When the timer is near the end, a native notification will suggest you to cancel the timer or extend it by 10 minutes. If no action is done by the end of the timer, the Mac will go to sleep.

Now, with custom timer option!