Follow the steps below to use the add-ins.

(1) You draw multiple circles on the sketch so that the pitch circles are adjacent to each other.

(2) You execute the add-in "Multi helical gear".

(3) You select multiple pitch circles in an order that takes into account the meshing relationship.

(4) You set various parameters of the helical gear.

(5) You execute the add-in "Multi helical gear".

Install:
The installer that ran when you downloaded this app/plug-in from the Autodesk App Store will start installing the app/plug-in. Or, simply double-click the downloaded installer to install the app/plugin.

Uninstall:
You can unload the add-in without uninstalling it by clicking the "Stop" button when the add-in is selected in the list box on the "Add-Ins" tab of the "Scripts and Add-Ins" dialog.
Unchecking "Run on Startup" causes the add-in not to be loaded in future sessions of Fusion.

To uninstall this plug-in, exit the Autodesk product if you are currently running it, simply rerun the installer, and select the "Uninstall" button.
Or, you can uninstall it from 'Control Panel/Programs and Features' (Windows 10/11), just as you would uninstall any other application from your system.