There's nothing you can do without recharging money

25 plus 198, recharge the monthly card every month, buy levels in four months, when the ninja comes out, then the coins can be used to replenish

You can get it by adding a few dozen yuan to 198.

If you want to replenish it later, it will be more troublesome. After that, you have to recharge 25 plus 198. Before 80 pieces, you can exchange 25 coins for one piece. After 80 pieces, you can exchange 50 coins for one piece.