Please go to your wplms-customizer.php file in wplms customizer plugin or functions.php in your child theme and add the following code at the bottom of the file.
add_action('wp_footer','wplms_fix_course_pricing');
function wplms_fix_course_pricing(){
if(!is_singular('course'))
return;
?>
<style>
.widget.pricing.fixed{
position: fixed;
top: 80px;
z-index: 99;
}
</style>
<script>
jQuery(document).ready(function($){
var windowWidth = $(window).width();
if(windowWidth >= 768){
$(".widget.pricing").each(function(){
var $this = $(this);
var height = $this.height();
var footer_top = $('footer').offset().top;
var left = $this.offset().left;
var width = $this.width();
$(window).scroll(function(event){
var st = $(this).scrollTop();
if(st > height && (st + height + 70) < footer_top ){
$this.addClass('fixed');
$this.css('left',left+'px');
$this.css('width',(width+30)+'px');
}else{
$this.removeClass('fixed');
$this.attr('style','');
}
});
});
}
});
</script>
<?php
}