There are usually two types of Community Goals: delivery missions and combat missions (bounties or combat bonds). You're able to filter prospective multi-crew sessions by their activity, and Community Goals are always listed in these filters.
Assuming you have signed up for the correct goal, after you join a multi-crew session, what do you have to do to correctly cash in on the goal?
E.g. for a delivery goal, do you have to be in the ship when it purchases the goods, or just when it turns them in, to get credit? I know you have to be in the crew to receive combat bonds, but what are the possible ways to cash them in? For the current combat bond goal, I noticed this text:
That makes it sound like you have the combat bonds tied to your account even when earned by a crew member, but do you lose them if the session ends early? Do you have to stay in the session until the pilot returns to the destination, or can you leave the session and turn them in at your convenience?
EDIT: I can confirm now that on a CG such as the one pictured above, you cannot leave the session before handing in Bounty Vouchers if you want credit for the CG (they are cashed in as part of the "after session report", and you have nothing to cash in at the station after you're back on your own ship).
It seems like you have to ride to the station with the host and have the host hand in vouchers (because crew members can't access Station Services menu). But, I can't confirm that will get you credit for the CG either, because personally the pilot either ends the session, or I get kicked before it ends, or they just don't go back to the station before I have to stop playing the game.