1. Add ihp-zip and zip-archive to the haskellDeps in your default.nix:

   let
       ...
       haskellEnv = import "${ihp}/NixSupport/default.nix" {
           ihp = ihp;
           haskellDeps = p: with p; [
               # ...
               ihp-zip
               zip-archive
           ];
       ...

2. Run make -B .envrc
3. Add IHP.Zip.ControllerFunctions to your Web.Controller.Prelude:

   module Web.Controller.Prelude
   ( module Web.Types
   , module Application.Helper.Controller
   , module IHP.ControllerPrelude
   , module Generated.Types
   , module IHP.Zip.ControllerFunctions -- <------- ADD THIS EXPORT
   )
   where
   
   import Web.Types
   import Application.Helper.Controller
   import IHP.ControllerPrelude
   import Generated.Types
   import IHP.Zip.ControllerFunctions -- <----- ADD THIS IMPORT

In your action use it like this:

module Web.Controller.Users where

import Web.Controller.Prelude

import qualified Codec.Archive.Zip as Zip

instance Controller UsersController where
    action ExportAction = do
        archive <- ["FileA", "FileB"]
                |> Zip.addFilesToArchive [] Zip.emptyArchive

        renderZip "Export.zip" archive