php - I'm trying to add custom route in wordpress

I'm trying to add custom route in WordPress but it return "No route was found matching the URL and request method."

Here is my code add_action('rest_api_init', 'university_search_route');

function university_search_route()
{
  register_rest_route('university/v1', 'search', array(
    'methods' => 'WP_REST_SERVER::READABLE',
    'callback' => 'universitySearchResults',
  ));
}

function universitySearchResults()
{
  return 'Hello';
}

What I'm doing wrong here ?

Solution:

function university_search_route()
{
  register_rest_route('university/v1', 'search', array(
    'methods' => 'WP_REST_Server::READABLE', //probs the uppercase you had
    'callback' => 'universitySearchResults',
  ));
}

function universitySearchResults()
{
  return 'Hello';
}