LITRPG: A DISAMBIGUATION
LitRPG: Basically novels in which videogame statistics play a significant part. These can be based on people playing FIVR games, or people being transported to videogame worlds, or further future sci-fi situations, where everyone has nanobots or similar, which give them statistical readouts of their abilities and skills. The primary thing is, in addition to the normal sort of character development, there is also videogame style statistical character development.
Then there's near future sci-fi, which takes place primarily in a virtual world, (which doesn't necessarily touch on the actual stats and videogame style character progression) like ready player one, which is probably part of the litrpg genre, but might not be considered so by some people.
Probably Not LITRPG:
Other things that sound like they might be litrpg, but probably wouldn't fall under that label:
Choose your own adventure books, where reading it is a lot like playing an RPG (with admittedly limited options),
Also the newer online versions of this, where the author does one chapter, and leaves the readers with choices, they vote or roll dice or whatever, and the story moves forward.
And people playing Roleplaying games by writing out character actions and events. Some of these don't have any rules and are basically cooperative story telling. Some are much more structured, with complex rule systems.