Error 404 not found

Hi guys, could you please help me: I have a web software that I have in the url: [Moderator Note: Removed direct link to website], I can see the login page, but when I try to login it shows error 404 not found: File not found (404 error) If you think what you're looking for should be here, please contact the site owner. I do not know why this happens, I already created the database, I did the configuration of the files. Do you know what may be happening with my software and hosting? Regards