Bootstrap scrollspy is not working on appearing text

I have a checkbox and when that specific checkbox is checked it shows some text above:

 $('#pck-94').click(function() {
     $('#pico-info').toggle(this.checked);
  });

this wil toggle the text which works and than I wanted to set a scrollspy which scrolls to the text which appears when checkbox is checked here is the html:

<span id="pico-info">(het verjaardagsfeestje Pico Patat is voor kinderen vanaf 4 jaar en maximale lengte 1.30m)</span>

and this is the scrollspy code where the checked is never logged:

   if($('input#pck-94').prop('checked')){
        console.log('check');
        $('body').scrollspy({ target: '#pico-info' });
    }

Here a fiddle : LINK