The key of G minor
G A B♭ C D E♭ F
2 flats: B♭ E♭. Relative major: The key of B♭ major.
The triads of the key
i
Gm | ii°
A° | III
B♭ | iv
Cm | v
Dm | VI
E♭ | VII
F |
The seventh chords
i7
Gm7 | iiø7
Am7♭5 | IIImaj7
B♭maj7 | iv7
Cm7 | v7
Dm7 | VImaj7
E♭maj7 | VII7
F7 |
In practice the V of a minor key is almost always major, taken from the harmonic minor: D7 (V7), which carries the leading tone F♯.
G natural minor scale
Open it in the app: 6. Harmony, in G