You can install on both Desktop and on Mobile. The settings from each held in your streamlabs account. So you can access the more detailed settings via desktop and save, then they will be present on the mobile app too. You title your stream in the Youtube Stream Settings and that will be picked up and added to the Streamlabs initiated stream. It is as simple as going into the streamlabs app and clicking the go live button, you will then be connected and live streaming on youtube. Stream labs also has donation options for viewers to donate.
Here is a sample I streamed a few days back.