iOS - Contact and calendar sync

Hi,

I have my contacts sync on iPhone through the Tuta iOS app, how can I add contacts on my phone and have them added to my Tuta contacts and not in the local storage?

In a similar fashion, is there any way to sync the iPhone calendar with the Tuta one? The Tuta calendar app is not working properly on my phone and keeps taking 5 minutes to load my events everytime I open it.

Thanks,