-) Upvote Vegan content: This one goes without saying, but anytime for example a post from r/Vegan reaches frontpage, that is a fantastic opportunity to get more people to learn about Veganism. We should all upvote more! :)
(Here is a feed I created to easily find new posts from lots of Vegan/Animal Rights centered subreddits, so you can easily upvote content from all of them at once: https://www.reddit.com/user/amynase/m/vegan/ - Let me know if I should add any other subreddits.)

-) If you speak at least two languages: Help translate animal rights content with Vegan Linguists: https://veganlinguists.org/

-) If you have coding skills: Help code animal rights projects with Vegan Hacktivists: https://veganhacktivists.org/join

-) If you use Twitter/X: Respond to tweets of people who want to go Vegan through 5 Minutes 5 Vegans: https://5minutes5vegans.org/de

-) Submit groups to the animal rights map: If you are also active in street activism in your area: Check if the groups you know are listed on the animal rights map or submit them if they are not listed yet, so more people can find them: https://animalrightsmap.org/
(Full disclosure - I am involved in this project myself)

Just thought I'd share these, in case some of y'all haven't heard about them yet and want to do more online activism :)

Please share any other opportunities to do online activism you know of!