https://wiki.project1999.com/Magelo_Blue
or...
https://wiki.project1999.com/Magelo_Red
...depending on which server you play. Make sure you are logged into your P99 wiki account, as only the original account that set up the Magelo is able to edit the Magelo (to keep people from trolling other's profiles). If you've lost your P99 wiki account...
https://wiki.project1999.com/Special:PasswordReset
I have no idea how the wiki's Magelo would respond if you attempted to create a Magelo without being logged in. It likely would not have created the profile. That could be your problem.