As @camaker pointed out, this is not allowed at Disney races. If you want to try and score a bib legally, then you have a couple of options. One is to go the charity route. You can find the approved charities for this race at:
Your second option is to try to grab a couple of bibs if the race opens back up, which it occasionally does--randomly. Set an alert with Telegram or Dis cord. Those slots disappear within a minute or two.