The astra_scroll_top_icon filter allows you to update the Scroll To Top icon class.
Usage
// Filter callback function
function example_callback( ) {
// Process you code here
return variable;
}
add_filter( 'astra_scroll_top_icon', 'example_callback', 10 );
Example
/**
* Add custom class to Scroll To Top
*
* @return string $classes
*/
function astra_scroll_top_icon_callback() {
$classes = 'fa fa-angle-double-up'; // 'fa fa-angle-double-up' replace with your class
return $classes;
}
add_filter( 'astra_scroll_top_icon', 'astra_scroll_top_icon_callback', 10 );
Note: To use 『fa fa-angle-double-up』 class you need to enqueue Font Awesome to your theme.
Check out the doc that explains how to add custom PHP code using the child theme』s functions.php file.
Refer – How to Add Font Awesome Icons in Astra?