Responses
I think it may be "the villainess becomes tbe leading lady", in chapter 2 it vaguely matches your description, but they werent like friends, the other girl torments female in their last last life to the pint where female lead dies as revenge.
it's not in this site, I think... but thanks, I'll try in other platforms ♡
The other alternative name for the manhwa is "Even Though I’m the Villainess, I’ll Become the Heroine!" I thinks it's on this site by this name
two female high school students are standing in the rooftop of a school building, they're friends iirc, but one of them pushed the other off the edge. then things happened, one after another, they're both reincarnated/transmigrated in a novel that one of them read. this must be a revenge manhwa, tho I don't really remember anything besides this^