Set stream type at top to 'Custom Streaming Server' if not already set
Enter URL: rtmp://video1.earthcam.com/myearthcam
Enter Stream Key:
Click 'OK' button at the bottom of the window
4
If no source is present under 'Sources' tab to the right of 'Scenes', click '+':
In list that pops up, choose 'Video Capture Device'
Give new device a name (other default settings should be fine), then press 'OK' at bottom of window
Under 'Device' section, choose specific device you will be using for streaming
(again, default settings are otherwise fine), then press 'OK' at bottom of window
5
Finally, hit 'start streaming' button to the lower right to start up stream.
Once the instructions are complete you should able to see your stream at this link.
Additional instructions about audio and stream setup can be found on the OBS site, as well as more information about the capabilities of OBS Studio.