Export and publish, just go to File Export. Here are all the options for exporting your video. Set the name for it a location to save it. You can use a preset for exporting the video and even create your own preset. After you select the preset you can customize it and change any of the video and audio settings. You can also manage the presets and select which one you prefer to appear in the default presets box.

Next is the scale bar. Make sure you have it at 100% so you can export it at the full size of the video. Using motion blur gives a smooth look to the motion in your videos. Next, hit export. If you and if you have notifications set in your Mac you will receive an indication was the export finishes. You can also publish to YouTube Vimeo or other providers