To install:

Go to C:\Users\*User name*\AppData\LocalLow\Kinetic Games\Phasmophobia
SaveFile.es3 and SaveFile.es3.tmp.bak files delete
In the same place, saveData.txt file delete or copy to another location
saveData.txt file copy (from archiv) to the same folder
Go to Steam, right-click on the game, then properties and turn off Save Sync with Steam Cloud

Author: Remk