Once Internet access is available via SonicWall, it is recommended to register the SonicWall security appliance. When accessing SonicWall using HTTP and performing the registration on the device there would be an error message as shown below in the screenshot.
Perform the following to enable HTTPS management on a select interface:
Login to the firewall.
Navigate to Manage | Network | Interfaces.
Edit the interface that you want to manage via HTTPS.