The agreement he asked for is unreasonable. Now the labor law seems to stipulate that employees can't spend money on work clothes.
If you have evidence, you can go to the local labor department to apply for labor arbitration, or sue him in court.
But you may spend more time and energy.
Pay attention next time, 1. Don't spend money on anything or training, these are what the company should pay.
Even if it is a trial, there should be a contract, and the trial is paid. Even if you are unqualified and not formally employed, you will be paid because you have worked hard.
In addition, I suggest that you expose this company, which has been a fraud company since childhood, and you can't buy things from this company.