I use pretty the same example as documentation does.
My full code (literally nothing more):
import React from "react";
import { redirect, permanentRedirect } from 'next/navigation'
export default function Index(params) {
permanentRedirect('/licenseKeys')
}
For sure I can use redirect() function instead, but I need to mark this redirect as permanent.
I investigated the next/navigation file, and there is no permanentRedirect() function, only regular redirect().
This looks like some stupid mistake like "one wrong character", but I copy-pasted the example from Next.js documentation, and nothing changed. Maybe somebody knows where I am wrong? Or is it Next.js docs lie to us?

This function is documented but not released yet. It's already in the
canaryrelease. You can install it bynpm install next@canary(use at your own risk).The documentation of
peremanentRedirectis made two weeks ago in this pull request But, the function is not yet released in a stable release.