jquery find modal-header code example
Example: bootstrap 4 modal get event related target
$('#exampleModal').on('show.bs.modal', function (event) {
var button = $(event.relatedTarget) // Button that triggered the modal
var recipient = button.data('whatever') // Extract info from data-* attributes
// If necessary, you could initiate an AJAX request here (and then do the updating in a callback).
// Update the modal's content. We'll use jQuery here, but you could use a data binding library or other methods instead.
var modal = $(this)
modal.find('.modal-title').text('New message to ' + recipient)
modal.find('.modal-body input').val(recipient)
})