Add tokens

my_module.tokens.inc

/**
 * Implements hook_token_info().
 */
function my_module_token_info() {
  // Token types.

  $tokens['tokens']['<sub>']['<token>'] = [
    'name' => t("<token_name>"),
    'description' => t("<token_description>"),
    'type' => 'url',
  ];

  return $tokens;
}

/**
 * Implements hook_tokens().
 */
function my_module_tokens($type, $tokens, array $data = [], array $options = []) {
  $replacements = [];

  $url_options = array('absolute' => TRUE);
  if (isset($options['langcode'])) {
    $url_options['language'] = \Drupal::languageManager()->getLanguage($options['langcode']);
    $langcode = $options['langcode'];
  }
  else {
    $langcode = NULL;
  }
    foreach ($tokens as $name => $original) {
      switch ($name) {
        case '<token>':
          $token = <replacement_text>;
          $replacements[$original] = $token
          break;
      }
    }
  return $replacements;
}