Microphone, and the permissions Nico does not ask for

The microphone is the only permission Nico needs. Everything else below is optional, or is not asked for at all.

macOS asks once, and will not ask again

If you refuse the microphone, macOS remembers and there is no prompt that can bring the question back. Nico cannot make it ask. You have to grant it yourself:

System Settings → Privacy & Security → Microphone, and switch Nico on.

The reason this matters more than it sounds: a denied microphone does not look like an error. The recording completes normally and comes back as digital silence with no words in it. Nico says so in as many words — the microphone is returning silence — because on macOS that is exactly what a refusal looks like from inside an app.

The only proof is a recording with a level on it, so the Status screen has a Test that records one and shows you the level. Use it after granting: it is the difference between believing the microphone works and knowing it.

The other side of a call — optional

To record the person you are talking to as well as yourself, Nico needs Screen & System Audio Recording. macOS files system audio under screen recording, which is why the name mentions the screen; Nico does not look at your screen. It needs macOS 13 or later, and your own voice never needs it.

On some Macs macOS shows a recording indicator in the menu bar while this is capturing and on others it does not, depending on which route your Mac takes. The Status screen says which yours is, rather than leaving you to wonder.

If you refused it earlier, macOS will not ask again here either: System Settings → Privacy & Security → Screen & System Audio Recording.

Input Monitoring — only for some hotkeys

A hotkey that is a single modifier key — Right Option, or Fn — needs Input Monitoring, because nothing else can see a key held on its own.

A combination such as ⌃⌥Space needs nothing at all: macOS handles it as an ordinary system shortcut. If you would rather grant nothing, pick a combination. Nico only mentions this permission when your chosen hotkey actually needs it.

Accessibility is not on this list, and neither is anything else

Nothing in Nico types into other applications. A transcript goes on the clipboard, which needs no permission from anybody. So Nico never asks for Accessibility, and a Mac that has never granted it is a Mac where everything works.

If macOS still has an Accessibility grant for Nico left over from an older version, nothing uses it and it is yours to switch off.

If your workplace manages your Mac

Corporate device management can block the Accessibility and Input Monitoring grants outright. Nico needs neither, so a managed Mac is usually fine — but the microphone grant is the one to check with whoever manages it.