This is a Lightstream Labs feature. For info on enabling Labs features please visit this article
To add your TipeeeStream alerts and overlays, first visit the TipeeeStream website to copy the URL of the alert or overlay you would like to add.
Once you have this copied, return to your Lightstream project, click the “Add Layer” button, and then click on "Alerts". Afterwards, you'll want to select TipeeeStream and then paste the URL you copied earlier in for your layer.