Hi @nelitow!
We added an extra fieldset with a snipcart input (id=“ophaalmoment”) to the billing section. Additonaly we’ve added a link which activates the javascript plugin.
<billing section="bottom">
<fieldset class="snipcart-form__set">
        <div class="snipcart-form__field">
            <snipcart-label class="snipcart__font--tiny" for="ophaalMoment">
                Afhaalmoment in de winkel (Markt 16, Oedelem) 
            </snipcart-label>
            <snipcart-input name="ophaalMoment" id="ophaalmoment"></snipcart-input>  
        </div>
      <a href="javascript:AddDatePicker()" id="kiesdatum" class="button secondary">Kies een datum</a>
</fieldset>
</billing>
Upon clicking the link, the AddDatePicker() function is executed. It adds a datepicker component to the rendered input which we can find by using the first input child .
To be sure, the rendered input value is set an extra time.
<script> 
/* OPTIE 3 datepicker met js-datepicker: https://github.com/qodesmith/datepicker#readme*/
      
      function AddDatePicker(){
        // zoek de juiste inputbox
        let firstInputChildIDValue = $("#ophaalmoment input:first-child").attr('id');
        
        // zet de inputbox als vereist
        $('#'+ firstInputChildIDValue).prop('required',true);
 
        // de vroegst mogelijke datum om op te komen halen
        var firstpossibledate = new Date();
        firstpossibledate.setDate(firstpossibledate.getDate() + 2);
        console.log("firstpossibledate "+ firstpossibledate )
        
        try {
        const picker = datepicker('#'+ firstInputChildIDValue, {
          startDay: 1, 
          minDate: firstpossibledate,
          disabler: date => (date.getDay() === 1), // Disabled every Monday
          customDays: ['Zo', 'Ma', 'Di', 'Woe', 'Do', 'Vr', 'Za'],
          customMonths: ['Jan', 'Feb', 'Maa', 'Apr', 'Mei', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
          onSelect: (instance, gekozendatum) => {
		// Do stuff when a date is selected (or unselected) on the calendar.
              	$('#'+ firstInputChildIDValue).val("afhalen op "+ gekozendatum);
		}
        });  
        console.log("kalender toegevoegd aan de input met ID:"+ firstInputChildIDValue );
        }
        catch (e) {
        console.log("kalender toevoegen niet gelukt");
        }
        finally {
        $('#'+ firstInputChildIDValue).focus();
        }    
      };
</script>
I hope this gives you some insight into our problem.
Thanks!