According to an ancient Greek legend, who was the first vampire to appear in history?

Ambrogio, a young man who was punished by Apollo for daring to fall in love with Selene, a woman the god himself fancied. This curse caused him to be unable to be exposed to the sun. Trying to get this sorted, he asked for help from Hades - but fulfilling that task got him in the bad books with Artemis, who cursed him to suffer agony if in contact with silver. Finally, he got her help to reuinite him with Selene, but the price was having to kill her mortal body and drink her blood, so that she could become immortal. Selene became the moon, and Ambrogio the first vampire.

https://www.gods-and-monsters.com/vampire-origin.html

This isn't really an Ancient Greek legend though if the hero of it has a modern Italian name like Ambrogio. It is clearly a modern legend pretending that the traditional features of vampirism are tied to Ancient Greek gods, when they seem to be Slavic in origin.

It may be worth pointing out that https://en.wikipedia.org/wiki/Selene has not a single mention of Ambrogio or vampires. A look at https://en.wikipedia.org/wiki/Ambrogio also does not contain any reference to vampires (or Selene). The list of Ambrogios, while containing a British robotic lawnmower, does not contain any person earlier than St Ambrogio https://en.wikipedia.org/wiki/Ambrose who was born quite a lot later than the introduction of Selene into the Greek pantheon. I think the possible origin of this 'ancient legend' might be in a Harry Potter pastiche at fanfiction.net, but don't feel inclined to dig any deeper into the rehashings of this fairly certainly pseudo legend. There are definite references to the Ambrogio lawnmower and the saint easily found, but I have found nothing reliable for the 'vampire'. I may be missing something - feel free to prove me wrong.