Does anyone know how to write an application requesting the court to go to the public security department to take notes?

No need to write, just tell the judge directly. I need police records. Police regulations prohibit retrieval. Ask the court to retrieve it. The Civil Procedure Law has regulations on evidence, which can be read.

Article 64 of the "Civil Procedure Law" stipulates that parties have the responsibility to provide evidence for their claims.

The People's Court shall investigate and collect evidence that the parties and their litigation agents cannot collect on their own due to objective reasons, or evidence that the People's Court deems necessary to hear the case.

The People's Court shall conduct a comprehensive trial in accordance with legal procedures. Examine the evidence objectively.