JS add negative points field on quiz builder question field and get value via AJAX.

functions.php

<?php

function admin_footer_script_tes() {
	?>
	<script type="text/javascript">
		jQuery(function($){

			$(document).on( 'click', 'button.ld-node-header__points-form-toggle.ld-button-reset', function( e ){
				$(".ld-node-header__points-form .ld-question-points")
					.before( '<input type="number" min="0" name="points_neg" class="ld-question-points points_neg" value="1"> Negative Points' );
			});

			$(document).on( 'click', 'form.ld-node-header__points-form .is-button.is-primary', function( e ){
			    var neg_points = $(this).parent().find('.ld-question-points.points_neg').val();
			    var data_node = $(this).parents().find('.ld__builder--content').find('div[data-rbd-draggable-id]');
				
				// this contains question object. below is an example
				// {"points":1,"tipMsg":"","tipEnabled":false,"edit_link":"http://localhost/office/addons/learndash/wp-admin/post.php?post=10&action=edit&quiz_id=8","question_type":"laq_calculated_formula","answers":{"sort_answer":[{"points":0,"gradedType":null,"gradingProgression":"not-graded-none","correct":false,"html":false,"graded":false,"sortString":"","type":"answer","sortStringHtml":false,"answer":""}],"classic_answer":[{"points":0,"gradedType":null,"gradingProgression":"not-graded-none","correct":false,"html":false,"graded":false,"sortString":"","type":"answer","sortStringHtml":false,"answer":""}],"matrix_sort_answer":[{"points":0,"gradedType":null,"gradingProgression":"not-graded-none","correct":false,"html":false,"graded":false,"sortString":"","type":"answer","sortStringHtml":false,"answer":""}],"cloze_answer":[{"points":0,"gradedType":null,"gradingProgression":"not-graded-none","correct":false,"html":false,"graded":false,"sortString":"","type":"answer","sortStringHtml":false,"answer":""}],"free_answer":[{"points":0,"gradedType":null,"gradingProgression":"not-graded-none","correct":false,"html":false,"graded":false,"sortString":"","type":"answer","sortStringHtml":false,"answer":""}],"assessment_answer":[{"points":0,"gradedType":null,"gradingProgression":"not-graded-none","correct":false,"html":false,"graded":false,"sortString":"","type":"answer","sortStringHtml":false,"answer":""}],"essay":[{"points":0,"gradedType":null,"gradingProgression":"not-graded-none","correct":false,"html":false,"graded":false,"sortString":"","type":"answer","sortStringHtml":false,"answer":""}]},"correctMsg":"correct","expanded":true,"post_title":"Test Question","type":"sfwd-question","post_content":"asd asdasdasd","ID":10,"incorrectMsg":"incorrect","correctSameText":false}
			    var question_data = data_node.attr('data-rbd-draggable-id');

			    var data ={
			    	'neg_points' : neg_points,
			    	'question_data' : question_data,
			    	'action' : "my_action"
			    };
			    $.post(ajaxurl, data, function(response) {
			    	console.log(response);
			    });
			});

		});
	</script>
	<?php
}
add_action( 'admin_footer', 'admin_footer_script_tes' );

add_action( 'wp_ajax_my_action', 'my_action' );

function my_action() {

	echo 'here: '. $_POST['neg_points'];
	wp_die(); // this is required to terminate immediately and return a proper response
}