Easiest way to export an Inventor file to IFC:

Open an assembly or part file, specify the file name, select schema version, check export properties in options and

press Export IFC button.

The plugin has also possibility to use Class and Property Mappings.

With Class Mappings the user can tell the plugin which IFC element type to use for individual parts.

With Property Mappings the user can map Inventor design tracking properties to standard BuildingSMART property sets.

Online help: 

https://codemill.fi/navistools/inventor/webframe.html#Using%20IFC%20Exporter%20plugin.html

The installer that ran when you downloaded this app/plug-in from Autodesk App Store will start installing the app/plug-in. OR, simply double-click the downloaded installer to install the app/plugin. You may need to restart the Autodesk product to activate the app/plug-in. 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, click Control Panel > Programs > Programs and Features (Windows 7/8.1/10/11) and uninstall as you would any other application from your system.

Purchase a permanent license online

The permanent license cost of this plugin is 300€. If you find this plugin useful, you can purchase a permanent license anytime from: https://www.codemill.fi/purchases