[FFmpeg-user] merging webm and wav files to create mp4

[Edgar Cheney]

Hi All,
We are working on a web app (node.js) and can't seem to find a good way to merge a .webm video file and a .wav audio file to create an MP4 so we can run it on Azure media service. We felt ffmpeg would do the job, but we are struggling to make it work. Do you happen to have or know of any publications out there that could help us merge these two files into an MP4? 
Anything you can do would be really helpful. Thanks in advance!!
Edgar