# Page Not Found

The URL `2.21/start/upgrade` does not exist.

You might be looking for one of these pages:
- [Updating Portainer](https://docs.portainer.io/start/upgrade.md)
- [Updating the Edge Agent](https://docs.portainer.io/start/upgrade/edge.md)
- [Updating on Nomad](https://docs.portainer.io/start/upgrade/nomad.md)
- [Update & Rollback](https://docs.portainer.io/admin/environments/update.md)
- [Updating on Kubernetes](https://docs.portainer.io/start/upgrade/kubernetes.md)

## How to find the correct page

1. **Browse the full index**: [/sitemap.md](https://docs.portainer.io/sitemap.md) - Complete documentation index
2. **View the full content**: [/llms-full.txt](https://docs.portainer.io/llms-full.txt) - Full content export

## Tips for requesting documentation

- For markdown responses, append `.md` to URLs (e.g., `/start/upgrade.md`)
- Use `Accept: text/markdown` header for content negotiation