Does IBKR charge a minimum fee for currency exchange?

Have been using tiger for more than half a year and thinking of entering into IBKR due to the ability to trade in fractional shares. However, can someone advise if IBKR charges a minimum fee for exchanging currency from SGD to USD? I’m seeing a fee of ~3.6 USD which isn’t that great for me if I am going to DCA a small amount every month.. Please help and thanks all :)