The key of F minor
F G A♭ B♭ C D♭ E♭
4 flats: B♭ E♭ A♭ D♭. Relative major: The key of A♭ major.
The triads of the key
i
Fm | ii°
G° | III
A♭ | iv
B♭m | v
Cm | VI
D♭ | VII
E♭ |
The seventh chords
i7
Fm7 | iiø7
Gm7♭5 | IIImaj7
A♭maj7 | iv7
B♭m7 | v7
Cm7 | VImaj7
D♭maj7 | VII7
E♭7 |
In practice the V of a minor key is almost always major, taken from the harmonic minor: C7 (V7), which carries the leading tone E.
F natural minor scale
Open it in the app: 6. Harmony, in F