Article 32 of the Contract Law stipulates: "If the parties conclude a contract in the form of a contract, the contract is established when both parties sign or seal it.
The guarantee provided by a limited liability company is generally valid as long as it has the official seal of the company or the signature of the legal representative, because the information of the limited liability company cannot be fully disclosed. Although the guarantor has not personally signed it, as long as the official seal is true, the contract should still be regarded as true and valid. Unless the official seal is forged, or the contract is only signed by the legal representative and the signature is also forged, the guarantor cannot be exempted from the responsibility, otherwise it is generally impossible to remove the guarantor.
Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.