Hi, in BR9.1 it is in the ([OPTIONAL] BRExtras) folder, it's folder's name is 100% save, replace the UserData folder with it's contents and voila, you'll have your chest with some items.
Warning: this will erase your userdata folder, so you'll have to back up, or start from scratch.
Also there is a new posibility ingame, BR9.1 comes with a new feature "Cheat Tools 2.9", just go to options menu, click Plugin Settings, and look for it, configure with any key combination you like, mine is configured on keyboard "g".
This feature alows you to change whatever you like in the game, from fast fishing, character mood, stars, levels, too many things to write here.
I hope it helps! Saludos!
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