DuitNow, QRIS, and PromptPay are cross-border payment services you can use to pay merchants in Malaysia, Indonesia, and Thailand. They use EMV specifications, which comply with global payment security standards, making them safe and convenient.
The foreign exchange rate is determined based on prevailing wholesale interbank rates or the government mandated rate, as determined by the respective card associations and/or payment service providers.
Currency conversions will incur a mark-up of 2% on top of the foreign exchange rate. The mark-up serves to cover services provided and administration by us and our service providers in connection with foreign currency transactions.
No. Apart from the conversion rate applied, you will not incur additional fees from using the service.
The acceptance mark should also be tagged to any of the following financial institutions (more institutions will join progressively):
You can do so at any merchants that display the QRIS acceptance mark on display at the merchant store front.

You may be encountering this error because you may have entered a non-whole amount in the payment amount in IDR (i.e 10,000.09 IDR). Simply input the payment amount as whole amount and try again (i.e 10,000.00 IDR).
There are two primary reasons why you might not have received cashback: