TJSGameSettings doesn't respect `onChange` option?

function dontShowWelcome() {
  game.settings.register(MODULE_ID, 'dontShowWelcome', {
    name: game.i18n.localize('GAS.Setting.DontShowWelcome.Name'),
    hint: game.i18n.localize('GAS.Setting.DontShowWelcome.Hint'),
    scope: 'user',
    config: true,
    default: false,
    type: Boolean,
    onChange: () => {
      alert('o');
    }
  });

class trackerSettings extends TJSGameSettings {
    this.register({
      namespace,
      key: "enable-tracker",
      options: {
        name: game.i18n.localize('Name'),
        hint: game.i18n.localize('Hint'),
        scope: "world",
        config: true,
        type: Boolean,
        default: true,
        onchange: () => {
          alert('o');
        }
      }
    });