Changed URL, how to fix it

Hi, so I did some research about this problem and none of those previous answers work for me, so I’m looking for some help here and hopefully work this out!
As you can see I did the rookie mistake of changing the sites URL and now I can’t login. This website was not mine but was passed down to me so I don’t know whether they have a backup database or not. Therefore I don’t know anything about cPanel or phpMyAdmin and most of the answers were talking about solving this problem using those tools. I don’t know what to do with this. Please help!! Thank you!!!

The page I need help with: [log in to see the link]