Shopify.REST.Client.request

You're seeing just the callback request, go back to Shopify.REST.Client module for more information.
Link to this callback

request(method, url, headers, body, opts)

Specs

request(
  method :: Shopify.REST.http_method_t(),
  url :: String.t(),
  headers :: Shopify.REST.http_headers_t(),
  body :: binary(),
  opts :: any()
) :: {:ok, response_t()} | {:error, any()}