The book states the following: The most complete surviving source about the playwright is a short anonymous work generally referred to as the Life. The contents of Life lines up with other ancient sources.
There's a translation here published by Mary Lefkowitz under the title 'The Euripides Vita', in Greek, Roman, and Byzantine Studies 20.2 (1979) pp. 187-210. The text is at pages 189 to 193.
Note that Life isn't a title in the normal sense, it's more a descriptor. For greater clarity it's best to say 'the Euripidean Life' or 'the Life of Euripides', or alternatively 'the Vita of Euripides' etc. Lives of this kind are valuable, but generally anonymous, generally dating to the Byzantine era, and in many cases they contain as much fiction as fact. I'm not familiar with this specific one, but Lefkowitz' commentary should steer you right.