JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="control" data-bind="value: input, valueUpdate: 'keyup'" />
<div data-bind="text: input"></div>
<div id="displaydiv"></div>
<script>
document.getElementById("control").onkeyup = function() {
document.getElementById("displaydiv").innerHTML = this.value;   
}
</script>

JavaScript

var viewModel = function() {
    this.input = ko.observable('');
};

ko.applyBindings(new viewModel());