HOW TO ADD AUDIO TO MP4

How to add audio to an existing mp4 file.  

Go to KAPWING.COM  and upload the MP4.  On the left side you will find an audio selection button. Select this button and record through your microphone the audio that you want.  When finished recording again go to the left button which says media. When this is selected an option to  select media  to add comes up. 

Click on the audio file and it will be superimposed on the video file.  At the upper right hand side there is a button to select called export project. Select this button and an additional option will be at the bottom export as MP4. You will have an option to view the file and download it to your computer. The program produces a URL with that project on it that anybody can access.

FROM THIS SILENT MP4

TO THIS MP4 WITH AUDIO

MP4 STARTED OFF AS A GIF ( USE https://ezgif.com/  TO CREATE MP4 FROM UPLOADED GIF)