how to set easy scroll in a tag in html code example

Example 1: smooth scroll css

html {
  scroll-behavior: smooth;
}

/* No support in IE, or Safari
You can use this JS polyfill for those */
http://iamdustan.com/smoothscroll/

Example 2: javascript go to top of page

window.scroll({top: 0, left: 0});
//Or with jQuery
$('html,body').scrollTop(0);
//with animation
$('html, body').animate({ scrollTop: 0 }, 'fast');