It's under Me/Kasa Lab as a Beta feature. (The 'Me' menu is in the lower right hand corner of the screen.)
I saw it today by accident when updating the firmware on one of my devices.
Coincidentally, about a week ago I switched to UD Mobile for my geofencing needs, as Alexa's geofencing (been using it for a few years) started giving me issues. So far so good with UD Mobile.
I have not enabled or tried Kasa's version.