Missing imapc plugin

Hi all,

I have an installation (experimental, for now) of Dovecot CE 2.3.21 on Ubuntu and I'm trying to sync messages with an external IMAP server using doveadm sync, but I get the message "Plugin 'imapc' not found."

It looks like the plugin isn't included in the version I'm using. Is that the case? Should I use a different version or download the plugin separately?

Thank in advance for your help