LMNT's AI Voiceover tool provides users with the capability to generate voiceover narrations for videos. To begin, users enter their LMNT API key and select a base voice from options like "David." The tool supports the upload of video files in MP4, MOV, and MPEG4 formats, with a file size limit of 200MB. The platform allows users to effortlessly combine the generated voiceover with their videos, and once the process is complete, the user can download the finished video. In addition to generating audio from provided scripts, users can upload their own videos for LMNT to incorporate the voiceover seamlessly. The tool includes a feature to create custom voices, providing users with a personalized touch to their voiceovers. The user interface is designed with simplicity in mind, utilizing drag-and-drop functionality for file uploads. It's noteworthy that using the tool without an LMNT API key results in a watermark on the generated video and longer processing times. Users are encouraged to create a free account to obtain their API key for an optimal experience. The tool also offers a demo app for user feedback on their Discord channel to influence future developments.