The Streaming Model prefab represents the model to be streamed inside your project. A Streaming Model component always needs a reference to the Stream Controller component to function and a Source URL which is the URL of your converted model. Once those two are correctly set, your model will start streaming inside your project as soon as you press Play.
The Stream Controller is a reference to the Stream Controller inside your scene and needs to be set, and the Source URL is the URL of your converted model that needs to be pasted in the field.
In case your project is using Light Probes, you can tick the Light Probe Usage box. In case you would like to use a custom material in your streaming model, you can tick the Custom Material box, which will open a new panel that will allow you to change the material.
You can also set different Quality Priority options by clicking at Streaming Runtime Options Settings. This means that some models can have higher priority of streaming than others, it can use only integer numbers and it works in the following logic:
0 = Highest Priority
1 = Lowest Priority
Any number larger than 1 = Higher Priority from the previous number, but still Lower Priority than 0.
You can also turn on or off the Streaming Model Preview script to check a preview of your streaming model in the scene without the need to play it.