I think they mean the esc button leading to the history in this game and in most visual novels the esc key leads to the save screen.
Noted! For OP and anyone else who may be wondering about it: We’re afraid you’re just going to have to use the save/load button as we aren’t able to go and change the keybindings now.
We’ll definitely keep this in mind for our next game though and try to make everything better. Sorry for the inconvenience!