Tailscale has [a guide for setting Tailscale itself up on Synology](https://tailscale.com/kb/1131/synology) and [a guide for obtaining HTTPS certificates using `tailscale cert`](https://tailscale.com/kb/1153/enabling-https). Surprisingly, neither documents the best solution, which is the [undocumented](https://tailscale.com/kb/1080/cli#configure-alpha) command
```bash
tailscale configure synology-cert
```
Prior to its introduction, [under this Tailscale issue](https://github.com/tailscale/tailscale/issues/4674) users came up with their own scripts, but using the official command is now the easiest way.
## Requirements
- Under the [DNS admin page](https://login.tailscale.com/admin/dns) make sure the following are enabled
- MagicDNS
- HTTPS Certificates
## Step-by-step
- [Set up Tailscale on your Synology NAS](https://tailscale.com/kb/1131/synology) or update it to at least **version 1.64.0**.
- Navigate in the Synology DSM to **Control Panel → Task Scheduler**.
- Create a new scheduled task with an user-defined script (**Create → Scheduled Task → User-defined script**) with the following details:
- **General**:
- Task (name): “Tailscale Certificate” (or whatever you want).
- User: root (the Tailscale command needs that).
- **Schedule**:
- “Run on the following days”: “Monthly”, “First”, “Monday” (should be frequent enough such that the 90 day Let’s Encrypt certificate is renewed automatically).
- **Task Settings**:
- User-defined script: `tailscale configure synology-cert` (the magic command).
- Press “OK” and follow on-screen instructions for setting up the root script.
- Right click on the created task and select “Run” to get the first certificate immediately.
- Navigate in the Synology DSM to **Control Panel → Security → Certificate**.
- You should now see a certificate for your `ts.net` subdomain in this list.
- Use the Tailscale certificate in one of the two ways, depending on your use case:
- Right click on the certificate and select “Edit”. Then tick “Set as default certificate” and press “OK”.
- Click “Settings” in the toolbar. Change the certificate on a per-service basis.
## Sources
[Tailscale HTTPS certificate on Synology NAS | Simmo Saan](https://sim642.eu/blog/2024/08/11/tailscale-https-certificate-on-synology-nas/)