Go there and pick your team (or if you're like me and dislike football or don't follow it, just pick a random one), then you just need to copy a code (to block those auto-submitter thingies), and that's it! It takes only a few seconds to donate a can.
ETA: There's a new drabble writing community which looks like a lot of fun. potted_meat! "Challenges posted each Monday consisting of one sentence taken from junk email and SPAM adverts." Any fandom.