Is it obligatory for a young man to pay the insurance fee for the Judo club that he no longer wishes to continue with, knowing that he does not want to confide in the coach?

If the insurance is impermissible, then it is not allowed to subscribe to it, even if that leads to leaving the club. If it is permissible, then there is no harm in subscribing. If the club is free from Sharia prohibitions, and an agreement has been made for training in exchange for a certain amount, then the subscriber does not have the right to terminate the contract before its expiry except with the approval of those in charge of the club.