Install nightwalker without plugin manager.
git clone https://github.com/stoichustler/nightwalker-vim.git ~/.vim/pack/plugins/start/nightwalkeradd this to your .vimrc
set termguicolors
let g:nightwalker_style = 'night' " available: night, storm
let g:nightwalker_enable_italic = 1
colorscheme nightwalker