If you have a hub, I’d recommend the vEdge Device Creator Edge driver from @TAustin for creating your virtual presence sensor(s). If you don’t have a hub, you can create a cloud based virtual presence sensor using the ST Advanced Web App.
I actually use the virtual presence sensors in my automation Routines so that I can change out the underlying geo-tracking method without having to touch all my Routines. I only have to change the two Routines that change the presence state for each virtual presence sensor. I used to use Life360, but once that went away, I’ve experimented with a number of different location tracking methods including the ST App, IFTTT, and Alexa App so it’s pretty easy to swap between them this way.