For anyone interested I have made a YouTube video on how to use Fusion 360 to create things with the Eleksmill. You can find it here - https://youtu.be/bbt2vceSfg4
You might also need to modify the grbl.cps file as mine did not stop the spindle motor at the end of the job. To do this copy the original grbl.cps file to either -
%appdata%\Autodesk\Fusion 360 CAM\Posts
if using Windows
/Users/Your User Name/Autodesk/Fusion 360 CAM/Posts
if using a Mac
Then edit the file and at the end of the file you need to add -
writeln("M5"); to the line before writeln("%"); at the very end as in the example below -
I also renamed the file my_grbl.cps to make sure I got the right one. Then in Fusion when producing the milling file in the Post Processor you need to select personal Post Processor and point it to that file.
Any problems let mme know and I'll try to help, but bear in mind I only started using Fusion a few days ago so I'm still figuring stuff out myself.