First clone the repo mentioned below.

Now go to the folder mentioned below:

%appdata%\Autodesk\Autodesk Fusion 360\API\Scripts

(copy it and paste in the file as shown below )

Create a folder named as “Dogbone”.

Now paste the file from the cloned repo to that folder.

Restart Fusion 360, and you will see the dog bone icon at the top as shown below.

Now you can use the dog bone for free.

Select the dog bone option and press Ctrl and click on the surface on which the dog bone needs to be applied.

The final result after the dog bone fillet is shown below.