If the company's attendance system clearly stipulates that you have to sign for work, you can't sign if you violate the system. Try to solve it through explanation and proof from colleagues. If not, the company will act according to the system, and you will only learn from the loss. Many units are like this, but some are signed, some are punched in, or fingerprints are signed in and so on. If there is no such explicit provision, it must be solved through the explanation and proof of colleagues.