Attach a pop-up form to a button

You can use a jquery event listener for this. You'll have to plug this into your theme just before </body> or add it into custom external js file you may have. You can hide the form by appending <form style="display:none;">

//Set event listener on contact us button

$('#contact-us').on('click',function() {

$(this).show();

});

Sorry, I forgot to show the bootstrap way of doing it

You can place the modal in the same place</body>. Disregard my last post. Use the below button which would call your data-target which is the id

Contact Button

<button type="button" class="btn btn-primary" data-toggle="modal" data-target="#exampleModal">
Launch demo modal
</button>

 
<!-- Modal -->
<div class="modal fade" id="exampleModal" tabindex="-1" role="dialog" aria-labelledby="exampleModalLabel" aria-hidden="true">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title" id="exampleModalLabel">Modal title</h5>
<button type="button" class="close" data-dismiss="modal" aria-label="Close">
<span aria-hidden="true">&times;</span>
</button>
</div>
<div class="modal-body">
...
</div>
<div class="modal-footer">
<button type="button" class="btn btn-secondary" data-dismiss="modal">Close</button>
<button type="button" class="btn btn-primary">Save changes</button>
</div>
</div>
</div>
</div>