JSFiddle - React, Tailwind, and code Playground

HTML

<body>                
<input type="text" id="text1" size="30">
<input type="text" id="text2" size="30">   
</body>

JavaScript

document.getElementById("text1").addEventListener("keyup", testpassword2);
document.getElementById("text2").addEventListener("keyup", testpassword2);

function testpassword2() {
  var text1 = document.getElementById("text1");
  var text2 = document.getElementById("text2");
  if (text1.value == text2.value) {  
    text2.style.borderColor = "#2EFE2E";
  }
  else {
    text2.style.borderColor = "red";
  }
}