Is the 2FA at nextcloud with Youbikey available at Free version - licencing

I am using Nextcloud service at domain. I would like to use two factor authentication with my YoubiKey.

Unfortunatelly I cannot see this option at web interface.
  1. Is this option available for Free version at Nextcloud or is it just not available option at service.

  2. Is this the same suituation with Collabora Online Office ?

Are those options available for Free version if there will be only up to 4 people at my cloud?

In general the function is freely available, but you need to install an additional app to get it enabled. If you cannot install additional apps, you should ask your hoster, why this isn’t possible or if he could install the app for you.

I cannot tell you if it also works with Collabora Office, but if you start the app from within Nextcloud, I would expected that it uses the Nextcloud authentication layer too.