Use renpy.session callbacks to sync the persistent file across devices via a server. Valve's Steamworks integration for Ren'Py handles this automatically if configured correctly.
: Depending on the game's configuration, you may see two different prompts: UNKNOWN_TOKEN renpy this save was created on a different device link
: To stop seeing the message for that specific progress, load the save (by clicking "Yes"), then immediately save the game again in a new slot. This generates a new security token linked to your current device. Why You Are Seeing It Use renpy