The invitation can be found underneath each post written by me, @gertu, @team-ccc, etc.
If you post in hive-166850 and use that invitation underneath each one of your posts (not only entries to contests) it's good for an upvote from @team-ccc

This is an Invitation to join #ccc. The community CCC supports members by encouraging and upvoting each other and by hosting contests. Contests are hosted by @team-ccc and it's members. See @team-ccc for contests running.