color Section class with gradient Background and a picture

But the “gradient” only makes sense if the other background image does not hide this gradient. Is there a png over it then?
Can you show a schematic how this should look like?

Or – if you like to have that “gradient” generated from background-color of the section to black :
https://enfold.webers-webdesign.de/test5/

you do not have a child-theme in use?
for the custom class there is an extra input field on the advanced tab – developer settings : custom css class
But insert it without a dot in front

if not – try to place it at the end of the parent functions.php just before:

// here is a good place for it

require_once( 'functions-enfold.php' );

there is an extra comment on that :

/*
 *  register custom functions that are not related to the framework but necessary for the theme to run
 */

but just one moment : i change the snippet a bit. …

#because the else clause lead to double insertion on parallax mode.
so here is a corrected snippet:

function add_gradient_to_section_bg_image() { 
?>
<script type="text/javascript">
window.addEventListener("DOMContentLoaded", function () { 
(function($){
	$('.avia-section.add-gradient').each(function() {
		var bgImg = $(this).css('background-image');
		var bgPos = $(this).css('background-position');
		if($(this).hasClass('avia-bg-style-parallax')){
			$(this).css('background-image', 'linear-gradient( to top, #8D005B 0%, #8D005B 90%, black 50%, black 100% )');
			$(this).find('.av-parallax-inner').css('background-color', 'transparent');
		}
		if($(this).hasClass('avia-bg-style-fixed')){
			var headerHeight = $("#header").height();
			$(this).css({
			'background-image' : ''+bgImg+' ,linear-gradient( to top, #8D005B 0%, #8D005B 90%, black 50%, black 100% )',
			'background-position' : '  '+bgPos+' , 0px '+headerHeight+'px',
			'background-color' : 'black',
			});
		} 
		if($(this).hasClass('avia-bg-style-scroll')){
			$(this).css('background-image', ''+bgImg+' ,linear-gradient( to top, #8D005B 0%, #8D005B 90%, black 50%, black 100% )');
		}
	}); 
})(jQuery);
});
</script>
<?php 
}
add_action('wp_footer', 'add_gradient_to_section_bg_image');