You can't do that, you have to find them through comment sections, click on their profile and follow them, and then you can message them on mangago or elsewhere, I'm pretty sure.
Go to Google and write <username> on mangago and it should pop up first
I had the same problem, so I just told them to comment under a manga (whatever it is) and then I added them, or I copied you mangago home and I sent it to them, like this: https://www.mangago.zone/home/people/1194113/home/
If you know their account name, you can go search it on google
Example: mangago user the gay cousin
Thank you everyoneeeeeeeヽ(*≧ω≦)ﾉ ♡♡♡
Does anybody know how to find other accounts? Like, I have a friend whom I'd like to send messages and random things to, but I don't know howwww