Is there a way to keep layers? I can't find the mask that is supposed to save

[Ertovarso]

Hello, I am trying to clean an image for a guy that works using photoshop, but he tells me that since I leave him with no layers, he can't use it.
I thought having the "enable download mask" would work, but I don't see any other file than the PNG, I don't see any other layer showing up on Photopea (I don't have/use photoshop).
So I guess he would want a layer with the original image intact.

EDIT: I was also wondering, how come files get bigger, going from 267 kb to 1,71 mb even if I am making the thing more white.

P.S.
I am glad I supported the program, it works very well, even if for some patterns it still can't maintain the texture so is a bit of a compromise.