GetStarted lv_timer_t

Hello I’m new and I try to compile the example “lv_demo_stress.c”
Where ist the declaration of “lv_timer_t” ?
When I ask lvgl it tells I don’t know what that is when I google
lv_timer_t it’s pointing me to the example github

static void obj_test_task_cb(lv_timer_t * tmr)


lv_task_t was replaced by lv_timer_t in v8.

Thank you kisvegabor