Where is lv_init()?

This is really newbie question. My very first work on lvgl.
I created small c code, and I added lv_conf.h + lvgl.h.
Then inside main() I added lv_init().
When I compile I get error: unresolved external symbol _lv_init referenced in function _main
I am just trying to get lvgl library to compile as first step. Then next step is to add microcontroller stuff, then the LCD stuff.
Where is lv_init() ?

Never mind. I found it.

In which file you found it. can you please share me the files or function definition