Create clean description attribute by removing html, VC en DIVI markup etc.

alter_feed_atribute_description

/**
 * Create clean description attribute by removing html, VC en DIVI markup etc.
 * @param array $attributes variable is an array that contains all the product data that goes into the feed.
 * @param Int $feed_id makes it possible to only edit a specific feed. You can find the id of a feed in the url of the Feed Editor
 * @param Int $product_id makes it possible to select a specific product id that you want to filter.
 * @return array.
 */
function alter_feed_description_item( $attributes, $feed_id, $product_id ) {
	
	// Remove WordPress shortcodes from Description
	$attributes['description'] = strip_shortcodes( $attributes['description'] );
	
	// If you use Visual Composer markup in your product descrioptions you can remove Visual Composer markup with the next code.
	$attributes['description'] = preg_replace("/\[(\/*)?vc_(.*?)\]/", '', $attributes['description'] );
	
	// To remove Divi markup in your product description use the below preg replace.
	$attributes['description'] = preg_replace("/\[\/?et_pb.*?\]/", '', $attributes['description'] );
  
  	// Only use the first 500 caracters from a string and append with ...
  	$attributes['description'] = mb_strimwidth($attributes['description'], 0, 500, "...");
	
	// IMPORTANT! Always return the $attributes
	return $attributes;
}

add_filter( 'wppfm_feed_item_value', 'alter_feed_description_item', 10, 3 );

If you're not familiar with using filters in your wp-admin, the best and easiest way to do this is by using a plugin like "Code Snippets" (https://wordpress.org/plugins/code-snippets/). Here you can find a great video explaining the use of this plugin https://www.youtube.com/watch?v=I1_ZqnQmwJs. ​ ​

After activating the Code Snippets plugin you can use the code to add the functionality.