Many flutes, especially in the beginner range, come with a split E mechanism.
On a flute without a split E-mechanism, playing high E (e3) can be a bit tricky. The split E mechanism significantly improves the responsiveness. You can recognize if a flute has a split E mechanism by the additional lever between the second G key and the F# key. This lever closes the second G key when playing high E.
If you play a high E on a flute without a split E mechanism, the second G key remains open. However, most professional flutists tend to skip using the split E mechanism since they can achieve these notes with good technique even without it.