max lenght for title field

You can set max title length using this code

add_filter( 'adverts_form_load', 'set_title_max_length' );
 function set_title_max_length( $form ) {

     if( $form['name'] != 'advert' ) {
         return $form;
     }

     foreach( $form["field"] as $k => $field ) {
         if( $field["name"] == "post_title" ) {
             $field["validator"][] = array(
                 "name" => "string_length",
                 "params" => array(
                   "max" => 100
                 )
             );
            $form["field"][$k] = $field;
         }
     }

     return $form;
 }

where 100 is max text length.