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

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

Once reaching the Dropbox upload dialog, you can choose assorted settings that will be applied to the uploaded video. After making your selections click on Link to Dropbox..., this will open the Dropbox Authorization dialog.

Once the Authorization dialog appears, login to your Dropbox Account, and follow the prompts to allow the application to access your online profile.

After authorization is complete, you can click the Upload button to commence the conversion (if required) and upload process.