@fightfascism
The important thing for using steganography is that the person who receives the message knows where to look for it, but no one else does.
You can pass a message in the most ridiculously simple ways: A rock moved or turned a certain way, a lapel pin turned slightly to the left instead of slightly to the right, scratching your ear vs your nose... These are things that can communicate short messages in real time with other parties who are present remaining oblivious. But the code must be known *in advance*.
Get with your friends and figure this out now. Don't wait till disaster strikes. And do it in a private way; online communications are not safe.