JSFiddle - React, Tailwind, and code Playground

HTML

<form action="">
  <input type="checkbox" class="checkbox" id="button1" />
  <input type="checkbox" class="checkbox" id="button2" />
  <input type="checkbox" class="checkbox" id="button3" />

  <input type="submit" value="Checkout" id="submitbutton" disabled="disabled"/>
</form>

JavaScript

$(function(){
    // on change event
    var bool;
    $("input.checkbox").change(function() {
        bool = $(".checkbox(:checked)").length !=1;
    // enable/disable
       $("#submitbutton").prop('disabled', bool);
})
});