Help Guide › Owner
Settings → Business Info → Currency sets the currency for everything: prices, reports, receipts, price lists, exports — and your resellers' phones, since they settle up with you in your money.
It changes how amounts are written, not what they are worth. Switching from dollars to pounds does not convert anything; 40 stays the number 40. There is no exchange rate anywhere in the app, deliberately — a rate that silently moved would rewrite your history every time it changed.
It is your business's currency, not your phone's. Travelling, or a phone set to another region, never changes your books.