Settings saved.
Create an app at developer.intuit.com and paste its Client ID / Secret here. These are stored encrypted, never as plaintext.
Before connecting: add this Redirect URI to your Intuit app (Settings → Redirect URIs) — it's generated automatically from this site's actual domain, so it stays correct even if you move the site or tunnel it through something like ngrok.
Connected.
Enter and save your Client ID above first.