在javascript脚本中添加laravel对象验证码

I need to add my captcha in a pop up but there are some stuff that need to be handled. first of all as i get the captcha from back-end its a php class, and secondly i need to add the object in an external js script,

so far i assigned the object to a variable in my blade file as below:

<script>
var captchaVar = '{!! NoCaptcha::display() !!}'
</script>

and for pop up I have the following code in my script file

.confirm({
    title: 'Confirm!',
    content: '<div class="col-xs-12">
' +
             '<div class="cr-item">
' +
             '<label class="inl-blk">security code</label>
' +
             '<div class="inp area inl-blk">
' +
             + captchaVar + '
' +
             '</div>
' +
             '</div>
' +
             '</div>',
    buttons: {
        confirm: function () {
            $(this).submit();
        },
        cancel: function () {
        }
    }
});

I get NaN instead of captchaVar which should be

<div class="g-recaptcha" data-sitekey=""></div>

.confirm({
    title: 'Confirm!',
    content: '<div class="col-xs-12">
' +
             '<div class="cr-item">
' +
             '<label class="inl-blk">security code</label>
' +
             '<div class="inp area inl-blk">
' +
             captchaVar + '
' +
             '</div>
' +
             '</div>
' +
             '</div>',
    buttons: {
        confirm: function () {
            $(this).submit();
        },
        cancel: function () {
        }
    }
});

There was a plus too much in your code. It then created the NaN instead of the expected result.