Ooohhh cool I just found out how to do it. Do you use mobile or computer?
Mobile, ipad
There should be a flag icon somewhere on the left of your screen. Press that and scroll/look at the bottom. There is a upload option.
What manhua will you translate?
If u want to upload a manga:
https://www.mangago.zone/read-manga/mangago_how_to_guide/uu/br_chapter-4274/pg-1/
If u want to upload a new manga chapter:
https://www.mangago.zone/read-manga/mangago_how_to_guide/uu/br_chapter-4290/pg-1/
How to add manga guys?, i want to add chinese yuri manhua and translate it