How to unlock bootloader in LG G5 (H831)?

From my understanding, it’s not possible.
BUT, there is a video on youtube showing that it’s possible! (Not octopus box method).

It’s by a YouTuber called “Dr.E (Max Lee)”: How to Unlock Bootloader on LG Android! [Android Root 101 #1b] - YouTube

It’s just that, the site where he stored the files doesn’t exist anymore.

So where does one proceed from here ? Is there somewhere else that I can turn to?

I understand that the LG G5 is an outdated phone and developers have moved onto bigger and greater things but for a few people out there that still have this phone, it’d be great if we could unlock it.