# How can I test notifications in a dev environment? Transloadit will contact the specified `notify_url` when an Assembly is finished; if your development environment is behind a firewall, use [Cloudflare Tunnel⁠](https://developers.cloudflare.com/cloudflare-one/networks/connectors/cloudflare-tunnel/), [ngrok⁠](https://ngrok.com/), or the first-party [@transloadit/notify-url-relay⁠](https://www.npmjs.com/package/@transloadit/notify-url-relay) via `npx -y @transloadit/notify-url-relay` (the relay differs from tunnels by polling public status and forwarding terminal notifications to your local `notifyUrl`). If your workspace has multiple developers, each of them will need to supply a different`notify_url`. To overwrite the `notify_url` specified in your Template, use a hidden input field named `params` in your form to pass a new value. For more details, see our documentation on[Dynamic Assembly Instructions](/docs/topics/templates.md#overruling-templates-at-runtime). ## See also: [Why doesn’t Transloadit charge by the minute?](/docs/faq/charge-by-minute.md) [Can I have my own upload progress bar?](/docs/faq/customize-progress.md) [How to rename files when exporting them to cloud storage?](/docs/faq/how-to-rename-files-during-export.md)