A lot of Chinese manufacturers specify the Edge Cut layer for V-scores, but it’s always good to check with them.
JLCPCB: This is what a user reported: V-cut and rounded corners - #39 by kymatica
PCBWAY: I can’t find a page saying that but I had a panel of breakout boards for TSSOP/SSOP chips made and they said to use the Edge Cuts layer.
Ocean Smile, formerly LocoPCB: A review of Ocean Smile (formerly LocoPCB) PCB service | Ken Yap | Hackaday.io also Edge Cuts layer.
They may charge extra so one should always check.