How use javascript in animation?

Answer 1

learn the basics at:
https://www.w3schools.com/howto/howto_js_animate.asp

also check this channel, which make awesome animations with a Javascript librarie called p5!

https://youtu.be/AaGK-fj-BAM

Answer 2

look at p5js: a very useful js library developed to facilitate interactive animations and more.
https://p5js.org

Answer 3

Than Q very much