Interactive ios notification

How can I send a remote push notification to iOS from Firebase with 2 buttons like Skype has?

Currently I am sending this from my node server

const payload = {
  data: {
    sessionId,
    caller,
  },
  notification: {
    title: 'Study Companion Call',
    body: 'Someone is calling you',
    text: 'This is some text',
    sound: "default",
    click_action: 'com.example.INCOMING_CALL',
    content_available: '1'
  }
};
const options = {
  priority: 'high',
  contentAvailable: true,
  timeToLive: 30,
};

admin.messaging().sendToDevice(list, payload, options);

And I do get the notification on the device but I'm not sure how to add those buttons there?

via Jeggy