In this video, the code used to authenticate with the YouTube API and upload or update videos on the YouTube channel is explained. The server acts as a worker, executing a script when a video is marked for uploading. The Python script is then executed with the video ID. The function for uploading a video to YouTube includes setting the title, description, keywords, and privacy settings. Authentication is done through a function that gets the necessary configuration parameters and builds a client object using the tools provided by the official library.