The latest version of Ren'Py ( 8.1 & 7.6 ) has this feature called
Save Token Security
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. I'm guessing it has to do with that. I have not played this game myself so I cannot verify it. This was also mentioned in at least one other game thread which uses the latest Ren'Py 8.1.
I have token folder in my renpy folder too because of other games. There are 2 files inside, security_keys.txt & upgraded.txt. The upgraded.txt file lists the games that uses this feature. Keep the security_keys.txt as secret.