Connecting to your Renderro Desktop can be done in two ways - with a desktop application or your web browser. To connect with a desktop application you have to download the client, which you can find here.
After installing Renderro, go back to your Renderro Desktop and click the "Connect" button. This should open your Renderro desktop application. You will be asked to add an exception for the hostname. Add an exception to proceed.
You are now connected to Renderro!