nix-community.nixvim/docs/user-guide/faq.md

Frequently Asked Questions

How do I use a plugin not implemented in nixvim

Using a plugin not supported by nixvim, but packaged in nixpkgs is straightforward:

• Register the plugin through extraPlugins: extraPlugins = [pkgs.vimPlugins."<plugin name>"].
• Configure the plugin through extraConfigLua: extraConfigLua = "require('my-plugin').setup({foo = "bar"})";

How do I use a plugin not packaged in nixpkgs

This is straightforward too, you can add the following to extraPlugins for a plugin hosted on GitHub:

extraPlugins = [(pkgs.vimUtils.buildVimPlugin {
    name = "my-plugin";
    src = pkgs.fetchFromGitHub {
        owner = "<owner>";
        repo = "<repo>";
        rev = "<commit hash>";
        hash = "<nix NAR hash>";
    };
})];

The nixpkgs manual has more information on this.