There are 4 ways you can add 3D files or models to your scene.
1. The recommended way is to drag and drop the model into the hierarchy on the right of the Studio, this will add your model to your scene at (0,0,0).
2.You can import a file via the File Menu to the top left of the Studio, titled Import Asset. 3. You can drag and drop assets into the Assets Folder in the Files tab.
4. You can drag and drop a model directly into the viewport, a small blue circle denotes the location the model will be placed.