When I go back to my hometown, there is no health code, no mobile phone number, and no documents. The police station can't solve it.

Call the national health department. Health codes are based on real data and can be generated by citizens or people who have returned to work through online declaration and background audit. Back home, no health code, no proof of mobile phone number. If the police station can't solve it, I can find the national health department, that is, the hospital managed by the state.