SharePoint CSOM

intermediate

I have been looking high an low for an answer but I am at a loss..

I'm trying to use CSOM and PnP framework to find out where a site that has

Template

Template

set to

REDIRECTSITE#0

REDIRECTSITE#0

leads to.
Online I find that

site.Url

site.Url

site.Description

site.Description

should lead to its target location, but all I find in all of its data is where it originates from.

I have even tried to use a standard

GET

GET

on HttpClient (or fetch() in js) to follow the redirect, but since I'm using a certificate to authenticate to the tenant, I'm only running into

401 Unauthorized

401 Unauthorized

blocks.