How to pick up openUrl auth response in a non-electron desktop app?

I got into the exact same question myself in my attempt last week to build a non-Electron app.

Inspect the following from my example from https://dev.autonomi.community/t/how-to-handle-system-uri-response-in-the-main-js-process/1679/9:

The authenticator will call an executable with the URI as an argument. With customExecPath this executable and the arguments can be configured. If customExecPath is ['C:\main.exe'], then the authenticator will call C:\main.exe <URI response>. It’s then up to the executable to read the URI.

This is also the reason my minimum viable example is a little complex.

In short: The Authenticator spawns an executable with the URI response as an argument.