I’m trying to add custom route in wordpress

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';
}