I think there are some brushes in the 'texture' category, there's also a way to copy and paste images into Krita and make one color transparent, I do that sometimes! Filter > Color > Color to Alpha
So maybe you could find a paper texture online and make it transparent using the filter
hmm maybe paste one of these onto a new layer of your drawing? https://unsplash.com/s/photos/paper-texture
vid reminds me of this one where someone draws reisen from touhou with html: https://youtu.be/X0IW-57AkF8
omg plasticdino that video, still insane after all these years and even more now learning html
i love this