Lilu.kext

Hi! I am really new to the hackintosh community, and need some help. I was following a tutorial (link below), and it asked me to download the lilu kext files. I couldn't find it on this website, which the tutorial asked me to download it from. Where else can I download it from? And is it mandatory? Thank you!

Specs:
i7 9th gen (no processor graphics)
msi z390 gaming plus
nvidia gtx 1050ti
32gb ram (3200mhz)

Edit:
Sorry forgot to link the tutorial -