While you can already use XSplit Gamecaster to connect to YouTube Live directly, you may optionally want to use Custom RTMP to connect instead.
This guide shows you how to obtain the Stream Key and Stream URL from YouTube Live as well as set up the Custom RTMP account on XSplit Gamecaster.
Obtaining the RTMP URL and Stream Key:
On the Youtube homepage, click on your user photo then Creator Studio.
On the Creator Studio sidebar, click on Live Streaming.
Alternatively, you can go here directly by going to https://www.youtube.com/live_dashboard.
Scroll down to Encoder Setup, then click the Reveal button.
The Server URL will go to the RTMP URL field on XSplit Gamecaster.
While the Stream name/key will go to the Stream Key field.
Please make sure that you keep your Stream Key private.
Setting up Custom RTMP:
Click on the Accounts tab.
Under Live Streaming, click the button and select Custom RTMP.
Enter the RTMP URL and Stream Key you obtained above.
The Stream URL is optional. This can be a link to your YouTube channel page.
The Custom RTMP service you set will show as configured on the Accounts tab and you will be able to start streaming through the XSplit Gamecaster overlay.