Goto create menu and click on "create helical gear" button. Then, fill the required gear information as follows.

1) Select the module out of the given choices.

2) Then enter the helix angle in degree. (Should be between 5 and 45 degrees)

3) Select the gear ratio out of the given choices.

4) Select the pressure angle out of the given choices.

5) Select the number of teeth out of the given choices.

6) Then enter the face width.

7) Hit ok, and the app will create a helical gear.

Install:

The installer that ran when you downloaded this app/plug-in from Autodesk App Store has already installed the app/plug-in.

OR, simply double-click the MSI to install the app.

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 Autodesk® Fusion 360™.

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\Programs and Features' (Windows 7/8/8.1/10), just as you would uninstall any other application from your system.

For any invalid larger values the add-in might not create the gear appropriately but, you can still try.