With this workflow, you can generate synchronized audio for any video. Simply select a video, describe what sounds your scene would make in a natural language and it will generate the sounds and combines the audio with the video automatically.
This workflow is a slight modification of kijai's example workflow you can find here: https://github.com/kijai/ComfyUI-MMAudio
MMAudio's GitHub repository: https://github.com/hkchengrex/MMAudio