Do you need the guarantor's signature for the criminal case guarantee?
If the guarantor is an individual, the guarantor should sign and press the fingerprint, and the guarantor has no requirement (you can press it or not). If the guarantee exceeds one page, the guarantor had better sign at the seam.
If the guarantor is a company, the guarantor must seal it. If the guarantee exceeds one page, the guarantor must seal it.
Further reading: How to buy insurance, which is good, and teach you how to avoid these "pits" of insurance.