_FLARE.sty

If I read the song DEMO, I find that the song KEY is E
Is it wrong?
It should be Em, which is more reasonable. Do you have time to look at it?

E minor is a minor scale based on E (root), consisting of the pitches E, F♯, G, A, B, C, and D. Its key signature has one sharp. Its relative major is G major and its parallel major is E major.

So, E would be correct.

Although KEY is E
But the following are actually Em
Therefore, I think KEY should write G

With this song, it's reasonable to presume it is actually in the key of E minor.

You could just set the Key Signature to Em, with no Transpose.

(Incidentally, the song 'House of the Rising Sun' comes to mind with this style and basic chord progression)

Yes Em would be the correct key choice. We will fix that.