How do you

Does emailing them don't work anymore?

It should be the same kinda..... Just go to any manga and fill out the blanks. This could help:
http://www.mangago.me/essay/create/?thing_id=595&type=1

Oops wrong link
http://www.mangago.me/home/photo/12290977/

It is different from what I see on my laptop because the upload button was in the right side of the "Chapter Section" of a particular manga

Like this one:

Note: This is where the upload button was put
Chapters (2) (Upload Chapters)

Chapter 5 Apr 29, 2021
Chapter 4 Apr 23, 2021
Chapter 3 Apr 14, 2021
Chapter 2 Apr 07, 2021
Chapter 1 Apr 01, 2021

Ops I dont know how to upload pictures and it seems the format of my message was wrong

But its for new chp for the existing manga what abt I have to add new manga?

I cant figure it out though, sorry.

Im pretty sure u just go to a random manga, click the upload button and fill out the page for the manga

I hope this helps (●'◡'●)ﾉ
http://www.mangago.me/home/photo/5318652/

Note: click on the zoom button to make the image clearer :)

DED" tutorial http://www.mangago.me/home/photo/12290977/