A certificate called 'self-signed.pem' is included with the Thinfinity® Remote Desktop Workstation installation. You will find it inside the \cert directory, located inside the Thinfinity® Remote Desktop Workstation application path.
If you want to use this default certificate you should have the files set as the image below:
Note: Because this certificate is not issued by a known Certificate Authority (CA), the web browsers will warn you they can not verify its authority.