ACF Form and Redirect upon submission

Question

I would like to redirect the user to a payment link depending on what choice they make but it's not redirecting. Can anyone see why not please? The strange thing is though; when the post is published, they can edit the form from the frontend and it will then redirect upon saving.

add_filter('acf/save_post', 'stripe_payment_redirect', 20);
function stripe_payment_redirect($post_id) {
    
    $post_id = get_the_ID();    
    
    $current_status = get_post_status($post_id);    
    
        if (is_admin() || get_post_type($post_id) != 'post_type_listings') :
            return;
        endif;
       
        if ( have_rows( 'listing_payment_options', $post_id ) ) :
            while ( have_rows( 'listing_payment_options', $post_id ) ) :
                the_row();
                 
                $package_choice = get_sub_field( 'listing_package_options' ); 
                $featured       = get_sub_field( 'listing_featured_listing' );
                
                if ( $package_choice == '6 Monthly' && $featured == 1 ) : //'6 Monthly and Featured';
                    wp_redirect( 'https://buy.stripe.com/test_28o4jW3dGgpTaQwdQV' ); exit;
                elseif ( $package_choice == 'Yearly' && $featured == 1 ) : //'12 Monthly and Featured';
                    wp_redirect( 'https://buy.stripe.com/test_28o3fS15y6Pj7EkbIL' ); exit;
                elseif ( $package_choice == 'Yearly' ) : //'12 Monthly Only';
                    wp_redirect( 'https://buy.stripe.com/test_dR66s415y1uZ5wceUW' ); exit;
                else: //'6 Monthly Only';
                    wp_redirect( 'https://buy.stripe.com/test_14kbMoeWo0qVgaQ5ko' ); exit;
                endif;
        
            endwhile;
        endif;  

}