SearchWP is a great plugin to add AJAX-based Live Search on the site. It can be integrated with PowerPack Search Form using pp_search_form_input_attrs hook.

Parameters:

$attrs – an ARRAY containing a key-value pair of all the attributes required for a Search Form.

$attrs = array(
         'placeholder'	=> $this->settings->placeholder,
         'class' 	=> array( 'pp-search-form__input' ),
         'type' 	=> 'search',
         'name' 	=> 's',
         'title' 	=> __( 'Search', 'bb-powerpack' ),
         'value'        => get_search_query(),
);

$settings – an OBJECT containing all the settings for the Search Form module instance.

SearchWP can be integrated into Search Form by setting data-swplive attribute to true as shown below.

Place the below code in your current theme’s functions.php file.

   add_filter( 'pp_search_form_input_attrs', 'my_function_modify_pp_search', 10, 2 );

   function my_function_modify_pp_search( $attrs, $settings ) {
       $attrs['data-swplive'] = 'true';
       return $attrs;
    }