You can open the Twitter upload dialog via one of the following methods:

• From the Share Toolbar button menu. Click the Share drop down button. Select the Upload to Twitter option.
• From the File menu. Select the Upload Converted File item. Select the Upload to Twitter option.
• From the File menu. Select the Upload Original File item. Select the Upload to Twitter option.

Once reaching the Twitter upload dialog, you can choose assorted settings that will be applied to the uploaded video.

After making your selections click on Upload to begin the conversion (if required) and upload process.

If required, the Twitter Authorization dialog will appear and your web browser will open, allowing you to log in to the service.