Here's how to publish from uStudio to YouTube:
When you create a YouTube destination in uStudio, you will be prompted to select a Google account to publish to. Log in to the Google account associated with the YouTube account where you want your videos to be published. Once your Google/YouTube account is connected to a YouTube destination, all videos published to that YouTube destination will appear in the channel for that YouTube account.
After logging in, follow the prompts to authorize uStudio to publish to your YouTube channel.
Once a YouTube destination has been created and authorized, publishing a video to it is as simple as dragging and dropping a video from your studio gallery into the YouTube destination of your choice.
After you have asked uStudio to publish your video to your YouTube channel, click on that channel's destination on the left navigation panel. The video you just sent will show a "processing" message. Once YouTube has successfully published your video, hover your mouse over the video and you will see two links: "View" and "Unpublish" - Clicking on "View" will direct your browser over to YouTube, where you will see your video playing. Clicking "Unpublish" will remove the video from the YouTube destination in a few moments.