Need to re-purchase from store. After unlocking the junk used car task - talk to the hotel aunt, receive the garbage stall owner's WeChat, go to the hospital to complete the conversation, go to the river and use magnetic suction to pull out the bicycle - return the bicycle to the garbage stall owner to unlock the gameplay. After you run out of magnetic magnets, go to a general supermarket to buy them. You can buy them when they are on sale, which is cheaper, or you can buy more and store them for the day.