Using an application such as Clutch or transmission-remote, you can monitor and manage your transfers from any location on the internet. Leave this option unchecked if you are only going to be managing your transfers on your local machine.
See your remote manager's documentation for operating instructions.
For security purposes, you can password protect access to Transmission, as well as restrict access to a trusted list of external IP addresses. To add an address to the list, click the + button.