Positions are exposed to the portal via the "More actions to position" menu, i.e. not directly in the publishing channels as e.g. portals connected via XML data feed.
Candidates are automatically enrolled. You can find out which candidates have been imported (and information on which have been propsed and which have not and why) in the Candidate Import History menu (link)
💡 Candidates can only apply for a position in ATS Recruitis if the position has been posted on the fajn-brigády.cz portal directly from ATS Recruitis (otherwise there is no indication which position the candidate belongs to).