This guide explains how to create SRT files for videos using Node.js and the AssemblyAI API. First, set up your development environment by installing Node.js 18 or higher, creating a project folder, initializing a new Node.js project, and installing the AssemblyAI JavaScript SDK. Next, obtain an AssemblyAI API key and configure it as an environment variable on your machine. Then, transcribe your video file using the AssemblyAI SDK and generate the subtitles in SRT format. Finally, run the script to create the SRT file and customize the maximum number of characters per caption if needed.