Using the Mux Video API, the process of implementing an end-to-end direct video upload via an upload button involves setting up both a client and a server, where the server manages confidential environment variables and the client provides a file picker interface. Familiarity with Express API setup, Node, and React event handlers is beneficial. The procedure includes setting up a starter project, creating REST API endpoints, and writing logic for a React upload button to handle video uploads. Upon selecting a video file, a POST request is made to the server endpoint, generating an authenticated URL via Mux. The process uses Upchunk to manage uploading in chunks and handle interruptions. Verification of successful uploads can be done through polling API requests or checking the Mux Dashboard. This approach emphasizes securing Mux API keys and avoiding their exposure in source control, while efficiently managing uploads using the Mux Dashboard and Upchunk.