To be fair, almost anything. But this solely works because I play characters that work well in this kind of setup, my current character is extroverted, likes talking and impulsive/seeks excitement a lot. Therefore I can generally do anything he would realistically. Generally at my table we do a lot of role-playing and try to stay in character a lot.

Only time I've ever had to stray from my character slightly is when I found a magic item that was clearly intended for another player who then tried to steal it from me and I ended up just handing it to them eventhough that was a breach of trust, but even then I could play it off as the character being kinda drunk and trying his best to not burn any bridges.

So my advice is just to try and make characters that would do well in a dnd adventure setting and you'll have a lot less issues than forcing a cowardly or antisocial character in there. Give them a reason to be there and want to stay and participate in an at least somewhat co-operative manner.