JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <input type="checkbox" id="chk" data-bind="checked: ok"/><br>
    <input type="button" id="btnCheck" value="Check" data-bind="click: Check"/>&nbsp;&nbsp;    
    <input type="button" id="btnUnCheck" value="Uncheck" data-bind="click:Uncheck"/> 
</div>
<div>
    Value: <span data-bind="text: ok"></span>    
</div>

JavaScript

function MyViewModel() {
    var self = this;
    
    self.ok = ko.observable();
    
    self.Check = function(){
      self.ok(true);      
    }
        
    self.Uncheck = function(){
        self.ok(false);            
    }
};

vm = new MyViewModel();
ko.applyBindings(vm);