Plesk extensions add extra functionality to the control panel. As a reseller, you can install and manage extensions that benefit your customers (e.g., WP Toolkit, Sitejet Builder, or backup tools).

### Viewing Installed Extensions

1. Log in to **Plesk**.
2. Go to **Extensions** → **Catalog**.
3. The catalog shows available extensions. Installed extensions are marked accordingly.

### Installing an Extension

1. Go to **Extensions** → **Catalog**.
2. Find the extension you want to install.
3. Click **Install**.
4. Follow any configuration prompts.

### Popular Extensions for Resellers

- **WP Toolkit:** Manage WordPress installations across all customers.
- **SSL It!:** Free SSL certificate provisioning and management.
- **Sitejet Builder:** Free website builder for customers.
- **Imunify360:** Server-wide security and malware protection.
- **Monit:** Server monitoring and alerting.

### Important Notes

- Some extensions require a license or are not free. Check pricing before installing.
- Your hosting provider may restrict which extensions you can install.

### Troubleshooting

**Cannot install an extension:**

- Contact your hosting provider — the extension may require server-level installation or licensing.

### Related Guides

- [IP addresses](/hc/help/en/articles/how-to-manage-ip-addresses-in-plesk)
- [Mail server settings](/hc/help/en/articles/how-to-configure-plesk-mail-server-settings-as-a-reseller)
- [Migration manager](/hc/help/en/articles/how-to-transfer-accounts-with-plesk-migration-manager)