JSFiddle - React, Tailwind, and code Playground

HTML

counter: <input type="number" id="counter" data-bind="value: count" />

JavaScript

var vm = {
    count: ko.observable(0),
};

.applyBindings(vm, document.body);

setInterval(function() {
    vm.count(parseInt(vm.count(), 10) + 1);
}, 1000);