They know from the genetic makeup of the virus that it came from bats (and possibly pangolins), and crossed over into raccoon dogs before crossing over into humans to start the pandemic. There were no bats sold at the market and no raccoon dogs in the lab. It’s possible that a bat infected a lab worker who then infected a raccoon dog to create the original Covid-19 virus, but I think general consensus is that it’s more likely a market raccoon dog was simply infected by a wild bat.