This is an accepted solution.
Thanks so much for your question!
Currently, as we're seeing in your screenshot, the only payout currency available in Singapore is SGD.
While it is possible in some countries to change your payout currency, this requires you to have a bank account in the currency that you want to be paid in - in your case, USD. If you're curious, we have a full list of available payout currencies by country, which shows that most countries do only support a single currency. Bear in mind that this is not a reflection of the currencies you are able to accept as payment on your store and will only affect the currency in which you receive your payouts.
I hope this clarifies what you're seeing in your admin and please let me know if you have any other questions!