This sensor is a “smart” thing. It takes analog measurements and “translates” them into a digital stream of bits which then can be read on any digital pin as long you know what this stream of bits means (that’s a protocol). And this is where the mentioned libraries come in, since they spare you the need to understand the protocol, since they already do and give you high level access to the extracted data.
#include alone does not add the library to your project. You need to do that via the Library drawer (bookmark icon) and the INCLUDE IN PROJECT button.