JSFiddle - React, Tailwind, and code Playground

HTML

<body ng-app="myApp">
    <div ng-controller="MyController">
        <input type="text" ng-model="myVar1" ng-keyup="updateValue()" /> {{ myVar1 }}
        <br />
        <input type="text" ng-model="myVar2" /> {{ myVar2 }}
        <br />
        {{ myVar3 }}
    </div>
</body>

JavaScript

var myApp = angular.module('myApp', []);

myApp.controller('MyController', ['$scope', function($scope){
    $scope.myVar3 = $scope.myVar1;
    
    $scope.updateValue = function() {
        $scope.myVar3 = $scope.myVar1;
    }
}]);