I also added the lv_example_btn_1() example from the documentation with the following in event_handler() for some visual feedback:
digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));
The buttons are displayed, but the LED does nothing when I touch either of the buttons.
In the serial terminal, only the following is displayed:
Hello Arduino! (V8.0.X)
I am LVGL_Arduino
Setup done