Please follow these steps to import into Fusion360:
Import Symbols and Footprints
Launch Autodesk Fusion 360.
From the main menu, next to the Data Panel, click on File
Click on Open… and then Open from my computer...
Select the .lbr file downloaded from SnapEDA and click Open
The library will be loaded and from the Device tab, you will be able to see the symbol and the footprint, double-click to open them.
If you could only download a footprint, go to the Footprints tab and double-click on the footprint to open it.