how to give shadow in css which show it in that box code example

Example 1: css box shadow

/* offset-x | offset-y | blur-radius | spread-radius | color */
box-shadow: 2px 2px 2px 1px rgba(0, 0, 0, 0.2);

Example 2: box shadow javascript style change

document.getElementById("myDIV").style.boxShadow = "10px 20px 30px blue";