Is it permissible for an employee to subscribe to the health insurance fund of a government oil company, which relies on optional monthly deductions from employees, along with significant government support for the fund?

If the health insurance is a cooperative, solidarity-based system among the company's workers, such that each worker pays a contribution as a donation to compensate for damages, and any surplus goes to the fund, then there is no harm in it. However, if it is commercial, then it is not permissible to subscribe to it.