Hi Frenki,
I am Dave, I will help you with this.
Intel integrated graphics like Intel Iris Xe does not have any dedicated VRAM, it is only the driver that fools the operating system into thinking it has 128Gb of VRAM so you can install games and software, because Intel graphics is located on you Intel processor, it is only dedicated graphics cards (Nvidia, AMD...etc.) that have VRAM.
Intel graphics uses shared system RAM, and the amount it can share is usually up to half your system RAM and that amount is managed by Windows.