Installing language servers - neovim/nvim-lspconfig GitHub Wiki
Manually
The installation instructions for each server are in server_configurations.md. For the vast majority of servers, this is a one-time, one-line installation (npm i -g pyright, dnf install clang-tools-extra, brew install lua-language-server, etc.).
It is preferred to use your system package manager if possible, as this will handle automatic updates for you.