Step 1: Select Connect Socials in the left menu
Step 2: Select Connect
Step 3: Under Manual, enter the RTMP URL / Stream Key info.
For example, for YouTube the URL would look something like rtmp://a.rtmp.youtube.com/live2/your_private_streamkey
Example: rtmp://a.rtmp.youtube.com/live2/12345abcde
How to find your platform's stream key https://help.liv.tv/hc/en-us/articles/27615686538770-How-to-get-stream-key-RTMP-for-common-platforms
Step 4: Select Manual as your Streaming Platform