To enable SSL for your nopCommerce store, follow these steps:

1. Obtain an SSL certificate from a trusted certificate authority (CA).
2. Install the SSL certificate on your web server. For IIS, you can install it through the IIS Manager.
3. In your nopCommerce admin panel, navigate to Configuration > Settings > General Settings.
4. Set the Use SSL option to Yes.
5. Update the site's URLs in the store URL settings to include https:// instead of http://.
6. Ensure that your website’s configuration in IIS is set to enforce HTTPS redirection.