How to free mem of animation


I created an animation look like lv_obj_fade_in which has in lvgl library.
My app has 2 screen.
obj1 and obj2 are children of screen1.
when screen1 changed to screen2, I delete screen1, but how about mem of animation? must I do lv_anim_del before delete screen1?
|- obj1
|- obj2 ← has animation

Thanks for your help!