How can I specify supported currencies in my payment app?

Hi,

I have a payment app that only accepts Euro but a test was made in another currency.

I would guess that there is a way to say that my payment app only works in Euro so that if a store has multiple currencies or a currency that my payment_app does not support it wouldn’t even show in the payment list but i have found no such place?

Is there a place to specify my supported currencies?

Or must i provide an error screen with the message and a cancel link leading to poor user experience?

Thank you.