return function(config) -- overrides `require("null-ls").setup(config)`
  -- config variable is the default configuration table for the setup function call
  local null_ls = require "null-ls"

  -- Check supported formatters and linters
  -- https://github.com/jose-elias-alvarez/null-ls.nvim/tree/main/lua/null-ls/builtins/formatting
  -- https://github.com/jose-elias-alvarez/null-ls.nvim/tree/main/lua/null-ls/builtins/diagnostics
  config.sources = {
    -- Set a formatter
    null_ls.builtins.formatting.stylua,
    null_ls.builtins.formatting.prettier,
    null_ls.builtins.formatting.deno_fmt.with {
      filetypes = { "markdown" },
    },
    null_ls.builtins.formatting.csharpier,
    null_ls.builtins.diagnostics.sqlfluff.with {
      extra_args = {
        "--dialect",
        "postgres",
        "--config",
        "/Users/kah/.config/sqlfluff/sqlc/config.toml",
      }, -- change to your dialect
    },
    null_ls.builtins.formatting.gofumpt,
    null_ls.builtins.formatting.goimports,
    null_ls.builtins.formatting.goimports_reviser,
    null_ls.builtins.formatting.golines,
    --null_ls.builtins.formatting.pg_format,
  }
  return config -- return final config table
end