ACF field in WP RSS feed

acf-rest-api-example.php

add_filter( 'rest_api_allowed_public_metadata', 'allow_my_metadata' );
function allow_my_metadata() {
  $allowed_meta_keys[] = 'audio_url';
  $allowed_meta_keys[] = 'start_station'; 
  $allowed_meta_keys[] = 'end_station'; 
  
  return $allowed_meta_keys;
}