This is the steps to use the app: 

• Navigate to the App Website.
• Click Autodesk Login button.
• Go to your Autodesk® BIM 360® admin account.
• Add integration to the app using the app Client ID.
• After that, your folders will appear on the left side of the screen.
• Click on of the Revit file and it will appear on the left side of the screen. 
• Click on the new screenshot button on the bottom.
• You can download the screenshot as is or edit it then download.