How to use the the-camp-lib.Relationship function in the-camp-lib

const password = process.env.USER_PWD || '';

  const traineeName = process.env.TRAINEE_NAME || '';
  const unitName = process.env.UNIT_NAME || '';
  const enterDate = process.env.ENTER_DATE || '';
  const birth = Number(process.env.TRAINEE_BIRTH || '');

  const cookies = await thecamp.login(id, password);
  const [group] = await thecamp.fetchGroups(cookies, unitName, enterDate);

  const trainee = {
    birth,
    traineeName,
    unitCode: group.unitCode,
    groupId: group.groupId,
    relationship: thecamp.Relationship.FRIEND,
  };

  const message = {
    title: 'Test title',
    content: 'Test content',
  };

  await thecamp.sendMessage(cookies, trainee, message);
})();