Ask a family member or friend.
Part I. General Instructions for Completing Certificates and ReportsThe funeral director or person serving in that role is responsible for completing and filing the death certificate. He or she shall obtain the necessary personal information from the best-qualified person and the medical certification from the person responsible for it. In most cases, the best-qualified person to obtain the personal information from—the informant—is a member or friend of the family. The following persons can be the informant and are listed in order of preference: spouse, parent, child of the decedent, another relative, or other person who has knowledge of the facts.
That might be relevant if we were talking about personal information. We're not.
"He or she shall obtain the necessary personal information from the best-qualified person and the medical certification from the person responsible for it."
The person responsible for the medical information is the doctor/medical examiner/coroner, and they, not the embalmer, complete the death certificate.
Which doesn't mention vaccination status.