Is the project of deducting a portion of one's salary and saving it with the company for three years, to be returned twofold, or to be retrieved without multiplication before the end of the period, considered usury (riba)?

The savings system practiced by some companies is permissible if it is with the employee's permission, provided that the funds are invested in permissible, non-usurious fields, and that the investment is subject to profit and loss, not a fixed profit. The described scenario involves a loan with interest, which makes participation in it impermissible (haram).