1. First of all, if the supervisor does not sign for fire protection construction, you can communicate with the supervisory unit to understand the reasons for not signing.

2. Secondly, you can seek the intervention of third-party authoritative institutions, such as construction authorities, audit institutions, etc.

3. Finally, complain to the regulatory authorities: You can complain to the relevant regulatory authorities and ask them to investigate and deal with the behavior of the supervision unit.