JSFiddle - React, Tailwind, and code Playground

HTML

<p>Destination country:
    <select data-bind="options: availableCountries, optionsText: 'value',
            optionsValue: 'key',
            optionsCaption: 'Any', value: selector"></select>
</p>

JavaScript

var viewModel = {
    selector: 2, 
    availableCountries: ko.observableArray([ {key:1, value:'France'}, {key: "2" ,value:'Germany'}, {key:3, value:'Spain'}])
};

ko.applyBindings(viewModel);