Signing a contract in person has the most legal effect.
What else is the content that the parties do not know? I wonder if I didn't sign it? If there is no signature, then the parties are not the counterpart of the contract at all. What don't you know?
——————————————————————————————————————————————————————————————
According to your ignorance, the parties have no debt relationship with this contract. The contract is invalid.
The signing of the contract is based on the expression of the true meaning of both parties. If not, the contract cannot be established at all, let alone the issue of effectiveness.