The LilyPI came with the lv_demo_widgets burned, but it’s fully a DIY product so it’s up to you to (fully) program your own project.
It seems it’s the same for all of their products (naked ESP32 board, PI, smartwatch, …) : as example
my own TWatch project.
They provided a “library” that embedded everything needed : chips drivers, lvgl, … but the problem is clearly to get documentation and tutorials … or even comments in source code 