You mapping look good.
But you have mapped against <leader>n which is by default: \n
Unless you have define: g:mapleader.
You can know the value of g:mapleader by running the following Neovim command:
echo "'" . g:mapleader . "'"
Some people (including myself) and some distributions (including NvChad, LunarVim, LazyVim, AstroVim) defines g:mapleader to Space
In such case <leader>n corresponds to Spacen