You will need to register a domain and obtain an SSL certificate for your Stream Manager. Set up SSL on Red5 Pro per this document.
Red5 Documentation for Product Owners and Managers
Red5 Features which Go Beyond Simple Streaming
Installation and Optimization Guides for Self-Hosted Solutions
Red5 APIs and Developer Documentation
Red5 Best Practices and Troubleshooting Guides
Streaming Protocols Supported by Red5 - WebRTC, RTSP, RTMP, HLS, SRT, MpegTS, and more
Red5 Pro Server and Streaming SDK Release Notes