How to add a sound effect into video online ?

1. Upload an intro image      record    and pause 
2.  Double click over the image to write caption “guess what sound it is?”
3. record the caption    and pause 
4. Upload    an “Hourglass video animation”
5. Open another browser tab and select sound from a free sounds online database (For example : https://freesound.org)
6. Go back to 011.video editor and click on  to capture the previous browser tab content. Make sure to select Share Audio
7. Return to the freesound.org browser tab and start to play
8. record then pause  your video and stop the sound playing as well.
9. upload      an image related to the previous sound
10. Record the image then pause    and download 
11. Repeat the same process for the next 3 sounds
12. When you have created your 4 video footages,  upload them    and record  them one after the other with a fade out transition
13. It’s finish pause    and download    your video

Here is the video made with sounds added in real time online