Yes you can access the router's configuration pages without being connected to the internet. The link you quoted (converted to "click here") is contained within the router, it isn't located on the internet.
OnePlus 5T review: Hands-on
Illustrator Andrés Lozano on his improv line work, brazen use of colours & hand sketching
iPhone X review
Comment envoyer gratuitement des gros fichiers ?