JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-app ng-controller="Ctrl">
<select class="span9" ng-model="proposal.formalStoryboard">
<option value="false">Not Included</option>
<option value="true">Included</option>
</select>
    <button ng-click="changeValue();">Click</button>
    <div>

JavaScript

function Ctrl($scope){
    $scope.proposal = {};
    $scope.proposal.formalStoryboard = true;
    
    $scope.changeValue = function(){
        $scope.proposal.formalStoryboard = !$scope.proposal.formalStoryboard;
        console.log($scope.proposal.formalStoryboard);
    }
}