LVGL8, The problem with scroll bars

lvgl6 has a “lv_page_set_scroll”, what does lvgl8 use to replace it? I need to customize the overall length of the scrollbar ,tks.
I want the overall length of the scrollbar to be shorter than the screen, for example, like this:

I’ve just update both lvgl and the docs to make it simpler.

It doesn’t look like it’s working yet, the part of the scrollbar that slides is indistinguishable from the overall background colour of the scrollbar.
For example, in the case of the image, I would like to achieve the effect that the scrollbar and the background of the scrollbar and the screen background are three colours, which is currently achieved by using two labels, which change proportionally when scrolling, to achieve a virtual scrollbar, is there a simpler way to do this? Thank you.

There is no “background” part for the scrollbars. So you can style only the rectangle drawn with white on your image.