Hi beeheemooth!
Thank you for answering me, but my problem is still not solved.
I will explain a little: I need a brush that draws solid pixels with a size of 1 but that does not have smoothing. There is a brush called '1 pixel' but it has smoothing. When I do what you say, I get the result I want! But definitely doing that is not viable because to make sprites I need to have precision while I draw. I want to make sprites for games, and I know how to do it in Krita, but I want to do it in opentoonz because I like it more. In any case, thank you.