Tea. Earl Grey. Hot.
Actually, no thanks, foul stuff.
I got a non-smart Breville "Hot Cop" machine. When activated by hand, it dispenses 500 ml of good boiling water from its spout, after 60 seconds.
If you don't want an exact multiple of 500 ml of boiling water at 60 second intervals then you are out of luck, and I find it more than I need - in fact I needed extra-large cups. But a current model of the machine now allows the quantity to be varied. But, as far as I know, not verbally.
It just occurred to me, maybe I could put glass marbles or something in the machine and get less water out. (Is that what they've done?) Supposing that I can buy Pyrex marbles...