where can i see backup file?

[MYu.1]

https://sips2017.sciencesconf.org/data/STM32CubeIntro_demo.pdf

50page show backup files.

it explains that backup folder exists in Src folder in Project folder.

but i check backup previous generated files when re-generating.

but i can't find backup folder in src folder in project folder.

where can i see backup folder.

i spend about 1 hour from finding backup folder, but i can't backup folder.

also, where can i find stm32cubeprogrammer.pdf like https://sips2017.sciencesconf.org/data/STM32CubeIntro_demo.pdf .

I am appreciated that it explains everything wonderfully and perfectly.