Can't Find / Log In To Website

This may be the stupidest issue ever, but here’s the deal. I spent the last week creating a site for a friend of mine, and then I followed the instructions to do the domain mapping. I’ve changed the Name Server information in their hosting site as per the WP instructions, got confirmation that the change was made, but and now I can’t even get to the WordPress Login Page for the site … https://www.kenziegrant.ca/wordpress/wp-admin. In fact, the URL doesn’t work at all.

I have no recollection of creating a user account for them, but I MUST have to install the theme and create the site. But when I enter their user name and password (what I think it is, it says there is no record of it). I need HELP! How do I access the site now?