So I have just started reading about the Neapolitan 6th, & I'm new to this topic. I know that it is generally used in its first inversion, & is often followed by chord V. Thus it is used in the bII - V - i chord progression (with bII being in first inversion).
A website mentioned about writing this chord in a cadence. It said:
Double the third of the Neapolitan 6th chord. The lowered second scale degree always moves down to the leading tone.
Is this what is generally done while writing the Neapolitan chord? Do you need to double only the 3rd of the chord, or is it possible to double the root of the chord?