You don't need any registration certificate, but you can get the resignation certificate, which was issued by the human resources department of the company when you resigned to prevent contract disputes.
If the file has no receiving place, you can first transfer it to the local talent market for archiving, and don't keep it in your own hands all the time, otherwise it will be hacked.
Generally, it can be put forward orally to the competent leader, and it will generally be kept. However, if you want to go, it is definitely not good to stay. If the company won't let you go, you can submit a written resignation letter to the competent leader. According to the labor law, you can leave your job automatically after one month without any responsibility.