Lv_theme_apply in 8.0 version

Hello i wonder to know , is there alternative in version 8.0.0 for lv_theme_apply ? ( And why in the folder themes is only lv_themes.h and not exist lv_themes.c.???

lv_theme_apply still exists in v8.

The theme implementations are inside their respective subfolders in src/extra/themes.

void lv_theme_apply(lv_obj_t * obj); - v8.0

previous was - void lv_theme_apply(lv_obj_t * obj, lv_theme_style_t name)

how now we can set modified style name, previous i used this - lv_theme_apply(volumeSettingsButton, (lv_theme_style_t)SETTINGS_IMG_BUTTON_THEME);

line 45 say than param name exist , but in function it does not exist;
previous it was void lv_theme_apply(lv_obj_t * obj, lv_theme_style_t name) , what is alternative for 8.0 , how i can set my custom style name ?))