PHP for custom back-to-top image stopped working

The website that I'm working with is https://www.nagareprivatestudio.com/. I have been using the code below to use a custom back-to-top image in the functions.php file. The back-to-top custom image had been working up until the last week or so. Any suggestions are welcome.

// Custom image in the Back to Top button
add_filter( 'generate_back_to_top_output', 'tu_custom_back_to_top_icon' );
function tu_custom_back_to_top_icon() {
printf(
'

<span class="screen-reader-text">%5$s</span>
',
esc_attr__( 'Scroll back to top','generatepress' ),
absint( apply_filters( 'generate_back_to_top_scroll_speed', 400 ) ),
absint( apply_filters( 'generate_back_to_top_start_scroll', 300 ) ),
esc_attr( apply_filters( 'generate_back_to_top_icon','fa-angle-up' ) ),
__( 'Scroll back to top','generatepress' )
);
}