insert Fusion 360 file into After affect

You can, but not directly. The files have to be exported from Fusion to a common 3D file format for animation programs like OBJ, 3DS and so on, then imported e.g. in the Cinema 4D Lite version that comes with AE to be used with Cineware or a commercial third-party plug-in like Element 3D. Of course you'll have to do a lot of extra work pretty much along every step of the way to fix conversion errors, re-apply materials and textures and so on.

Mylenium

Moving thread to the After Effects forum from Using the Community