why it showing double curency

why it showing double curency ?
on product module i have choose 1 curency.

That's because in your HikaShop configuration, the main currency is EUR.
Since you set your price in IDR in your product and that your main currency is EUR, the system is converting the prices to EUR. And since your didn't set any rate in your currency, the converted amount is the same as the original amount.
So the solution is simple: just set IDR as your main currency.